[neznan]

I have flash it with SE Tool 2 Lite and used those files:

W810_R4EA031_MAIN_GENERIC_HN_RED49
W810_R4ED001_FS_S_E_EUROPE_RED49
W810i_CDA102494_91_R3A_Mobitel customization

But GPRS still stops functioning.

I don't think that the problem is in antenna, because phone didn't never do problems during calls.