That's done it, I didn't get that the goldcard relates to the actual micro SD you use, thought the code was from the phone.
Updating now to the Orange UK so I will soon have UMA, Thanks for the advice.
successfully downgraded from 1.31 to 1.28 with goldcard and psneuter, used this tutorial for the DHD, instead of
./misc_version -s 1.31.405.6
i have used
./misc_version -s 1.27.405.6
i renamed the rom.zip to PG88IMG.zip. Put it on root of the SD Card and started the phone in to bootloader.
The bootloader loads the file and stop the setup after a while with the message that the rom is older then the one that is allredy installed.
i have a O2 branded ROM with the Version of RUU_Saga_O2_UK_1.31.206.1_Radio_20.28b.30.0805U_38 .03.02.14_M_release.
And the unbranded HTC Version is older RUU_Saga_HTC_Europe_1.28.401.1_Radio_20.28b.30.080 5U_38.03.02.11_M_release.
This means for me that a debranding with a GOLDCard is not possible due to the reason of the old release from HTC.
Does anyone know if there is a newer version of the HTC Rom?