W995 "Invalid Sim", Confusing. Please Read

When I put my o2 sim in my w995 it comes up "Invalid Sim"

I de-branded it using this guide:
Debranding A2 Sony Ericsson Phone tutorial/guide | SE Flashing

It said to backup customize.xml and preloaded_config.xml and as A2Uploader cant extract files from the W995. I used Codeclaw's "DB3210 CID53 File Xtractor" When I flashed the .bin to the phone I may have left the sim inside. After I had successfully backed up these 2 files I realised the phone now said "Invalid Sim". I didnt know what to do so I just carried on with the guide and copied Customize_upgrade xml to the phone via A2Uploader and updated my firmware with Sony Ericsson Update Service.

It is De-branded now but still says "Invalid Sim" I thought the sim could be damaged but it doesnt work with ANY o2 sim. I tried an Orange sim card and it worked fine. The Phone was original o2 and in service mode it says all networks are all unlocked.

Any posts are greatly appreciated, thanks.