Try this soft (it is only my idea):
http://mobile.efnet.org/software/ericsson/erTamp%20Clear%20v1.00.rar
on Marek Jilecek pages http://milacek.miesto.sk
Hi,
Do it fast and easy with "ErTool 17"! Works 100000%. Go to "special functions" menu choose "de-tamper" and follow instructions.
If it does not work at first time just flash phone (it will still be tampered) and then on "special functions" menu choose "de-tamper" and follow instructions.
Very easy and tested!
Regards
damaso@linus.uac.pt
PS. Ertamp clear never worked good for me!