Right, it will be something in the UMA settings on your 9800 that are at fault then. I do think that Crackberry may have the answers for you, they're a load of BlackBerry hacks and know their way around the technology. You won't be alone, thats for sure.

In the thread on here that talks about UMA I did quite a bit of work on the older Bold 9700. The principle is the same, but the specifics relating to your 9800 and the version of the OS you are on will be subtly different. I havent had a BB for a few years so my own knowledge is now dated.