Calls get stopped with a buzz

[Guest schteffe]

Currently I'm running the JapJelly RLS6, but I have previously tried both Fillyjonk and Pauls Modaco and I keep getting the same thing with all these ROMs. Sadly I never tried with the original (swedish Telia) ROM, was to eager to get to 2.2...

When I make a conversation, if i make the call or just answers doesn't matter, after a while (it varies how long, sometimes a few seconds, sometimes minutes) the phone starts to give away a buzz (sounds like an "eeeeeeeee", sometimes loud, sometimes quietly) and I can hear nothing and the one i talk to can not hear me. The sound keeps on even after i end the conversation and to stop it i have to restart the phone. The phone works in all other aspects. Any ideas? Thanks :D

[Guest schteffe]

Now I have also tried the Swedish Snow ROM and FLB Froyo G2 (R6) without any improvements.

*sigh*

Any ideas? Could it be some setting I could try?

I'm starting to think I'm screwed here. Is there any way to return the phone in it's original state, locked and with the original Telia ROM, so I can send it back?

This could after all be an error thats been there all along, but if they can see I've been rooting it I won't get any warranty right? :/