Glad the hard reset fixed it. I was going to suggest that next.
To me, WM6 is loads better. Less sluggish, better power management and it fully supports 3G.
If you use data (web browsing or email) then HSDPA on 3G is a HUGE speed improvement over GPRS and EDGE. Plus the "Connection Sharing" app makes it a breeze to tether a laptop and use your phone's internet connection on the go.
NOTE: If you use AT&T, they charge extra for a "tether" data plan. You can get around that by loading the UNbranded version posted in this forum instead of the official ATT update. The unbranded ROM also does not have all the ATT bloatware.