Worked great on my old K550i

Before
Code:
Action journal
17:30:37   Unlock network lock by reset
17:30:37   Unlocks the phone network lock by reset (up to OTP CID 53).
17:30:37   Operating system: Microsoft Windows 7 Ultimate Edition (build 7600), 64-bit
17:30:37   Application version: 0.10.2524
17:30:37 . The action name is 'Unlock'
17:30:37   Selected phone type: K550im
17:30:37   Selected connection method: USB ROM
17:30:37 i Instructions
17:30:37 i 1. Make sure the phone battery is charged to at least 50%.
17:30:37 i 2. Switch off the phone!
17:30:37 i 3. Remove the phone battery and wait at least 5 seconds before reinserting it!
17:30:37 i 4. Press and hold buttons 2 and 5, then connect the cable to the phone!
17:30:37 . The action started waiting for the user
17:30:43 . The action finished waiting for the user
17:30:43   Connecting via Generic EMP USB Flash Device (USB1)...
17:30:44   Device driver version: 2.2.0.5
17:30:44   Entering baseband CPU service mode...
17:30:44   Detected chipset: DB2020 '9900
17:30:44   Boot mode: ROM
17:30:44   Sending loader...
17:30:44   Waiting for loader response...
17:30:44   Flash chip manufacturer: Intel®
17:30:44   Flash chip ID: 897E
17:30:44   IMEI: 
17:30:44   OTP CID: 51
17:30:44   OTP area status: Locked
17:30:44   Product type: Retail
17:30:44   Effective CID: 53
17:30:44   Effective color: Red
17:30:44   Restarting the phone...
17:30:46 i Instructions
17:30:46 i 1. Make sure the phone battery is charged to at least 50%.
17:30:46 i 2. Switch off the phone!
17:30:46 i 3. Remove the phone battery and wait at least 5 seconds before reinserting it!
17:30:46 i 4. Press and hold buttons 2 and 5, then connect the cable to the phone!
17:32:07   Connecting via Generic EMP USB Flash Device (USB1)...
17:32:07   Device driver version: 2.2.0.5
17:32:07   Entering baseband CPU service mode...
17:32:08   Detected chipset: DB2020 '9900
17:32:08   Boot mode: ROM
17:32:08   Sending loader...
17:32:08   Waiting for loader response...
17:32:08   Establishing connection to the server...
17:32:18   Receiving news...
17:32:28 i No news
17:32:31   Actual credit: 0.00
17:32:49   Actual credit: 0.00
17:32:50   Effective color: Brown
17:32:50   Effective CID: 49
17:32:50   Restarting the phone...
17:32:52 i Instructions
17:32:52 i 1. Make sure the phone battery is charged to at least 50%.
17:32:52 i 2. Switch off the phone!
17:32:52 i 3. Remove the phone battery and wait at least 5 seconds before reinserting it!
17:32:52 i 4. Press and hold buttons 2 and 5, then connect the cable to the phone!
17:33:36   Connecting via Generic EMP USB Flash Device (USB1)...
17:33:36   Device driver version: 2.2.0.5
17:33:37   Entering baseband CPU service mode...
17:33:37   Detected chipset: DB2020 '9900
17:33:37   Boot mode: ROM
17:33:37   Sending loader...
17:33:37   Waiting for loader response...
17:33:37   Waiting for loader response...
17:33:40   Code NCK for relock: ....
17:33:40   Code NSCK for relock: ....
17:33:40   Code SPCK for relock: .....
17:33:40   Code CCK for relock: .....
17:33:40   Code PCK for relock: .....
17:33:40   Code ESLCK for relock: ....
17:33:40   Code NCK for unlock: .....
17:33:40   Code NSCK for unlock: .....
17:33:40   Code SPCK for unlock: ......
17:33:40   Code CCK for unlock: ......
17:33:40   Code PCK for unlock: ......
17:33:40   Code ESLCK for unlock: .......
17:33:40   Writing flash...
17:33:42   Effective color: Red
17:33:42   Effective CID: 53
17:33:42   Turning off the phone...
17:33:44 i Please disconnect battery and cable from the phone!
17:33:44 s Successfully done.
17:33:44 . The action entered shutdown phase
17:33:44 . The action reported success

Additional details
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05 30 31 E5 28 A2 F0 B1 76 41 74 43 B2 85 68 F7 
2E 19 2A 38 EA 93 E0 6F E6 7E 84 6D DE AB 51 9B 
CC BB 74 BB 5A CD D0 11 AA 55 8E 9D A8 60 
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...and after
Code:
Action journal
17:39:03   Identify
17:39:03   Shows detailed information about the connected phone.
17:39:03   Operating system: Microsoft Windows 7 Ultimate Edition (build 7600), 64-bit
17:39:03   Application version: 0.10.2524
17:39:03 . The action name is 'Identification'
17:39:03   Selected phone type: K550im
17:39:03   Selected connection method: USB EROM
17:39:03 i Instructions
17:39:03 i 1. Make sure the phone battery is charged to at least 50%.
17:39:03 i 2. Switch off the phone!
17:39:03 i 3. Remove the phone battery and wait at least 5 seconds before reinserting it!
17:39:03 i 4. Press and hold the button C, then connect the cable to the phone!
17:39:03 . The action started waiting for the user
17:39:25 . The action finished waiting for the user
17:39:25   Connecting via SEMC USB Flash Device (USB1)...
17:39:25   Device driver version: 2.2.0.5
17:39:25   Entering baseband CPU service mode...
17:39:25   Detected chipset: DB2020 '9900
17:39:26   Boot mode: EROM
17:39:26   Sending loader...
17:39:26   Waiting for loader response...
17:39:26   Flash chip manufacturer: Intel®
17:39:26   Flash chip ID: 897E
17:39:26   IMEI: 
17:39:26   OTP CID: 51
17:39:26   OTP area status: Locked
17:39:26   Product type: Retail
17:39:26   Effective CID: 53
17:39:26   Effective color: Red
17:39:26   Initializing GDFS access...
17:39:27   Reading from GDFS...
17:39:27   Phone type: K550i
17:39:27   Phone branding: Unknown
17:39:27   MAPP CXC article: R6BC002     prgCXC1250669_GENERIC_LI
17:39:27   MAPP CXC version: R6BC002
17:39:27   CDA article: CDA102743/58
17:39:27   CDA version: R6A
17:39:27   Default article: cxc1250671
17:39:27   Default version: R6BC002
17:39:28   Language package: VFE_3
17:39:28   The phone is not locked to a network.
17:39:28   Turning off the phone...
17:39:28 i Please disconnect battery and cable from the phone!
17:39:28 s Successfully done.
17:39:28 . The action entered shutdown phase
17:39:28 . The action reported success

Additional details
---
78 13 EC 0B 96 D8 7E 77 AC AB C6 23 50 8F 36 0F 
B4 83 20 68 28 C9 12 A9 44 54 56 AD 60 21 AF 1D 
92 7F 1E 95 18 89 A2 D7 34 FF 0D 0E B7 5A 
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I also checked it manually with >*<<*<* and there is no SIM lock