H, I'm trying to debrand a AT&T Sony Erricson Z750. I actually did this a while back but recently the phone messed up and was replaced now trying to get back into either the old or the new phone I get - Sorry, your phone is NOT SUPPORTED
Error: Failed to send CSLoader! Can anyone point me in the right direction please.

TIA
Tony

05:59:57| XS++ v3.1 (Darwin) Ready !
05:59:57| Executed on Microsoft Windows XP
06:00:56|
06:00:56| Attempting to open the interface...
06:00:56|
06:00:56| TURN OFF PHONE!
06:00:56| Hold 'C' button on phone and connect phone NOW.
06:00:56| You have 30 seconds...
06:00:56|
06:01:07| Baseband ID: C802
06:01:07| Protocol Version: 4.1
06:01:07| Phone name detected!
06:01:07|
06:01:07| Profiling SEMC phone...
06:01:07| Platform: DB3150
06:01:07| OTP CID: 52
06:01:07| EROM CID: 52
06:01:07| EROM Color: Red
06:01:07| IMEI: 35893701xxxxxx
06:01:07| Phone ID: Z750
06:01:07| Region: AMERICA-2
06:01:07| CDA: 1206-7735 R1A
06:01:07| Firmware Version: R1FA030
06:01:07| EROM: 1200-4341 SEMCBOOT R6A013
06:01:07| Ready for operation!
06:01:21| Sorry, your phone is NOT SUPPORTED
06:01:21| Error: Failed to send CSLoader!
06:01:21| FSX Shutdown!
06:01:23| Disconnected... Unplug the phone