The most important question - are you running apps under the ARMEL or X86 target ? ARMEL is for compiling only, if you try to run stuff you get problems like you described.
Important note - some, Fremantle specific widgets are not implemented yet. Most of them (especially those present in Diablo) are present and usable.
Make sure that your scratchbox has network connectivity. If it doesn't work for it, it won't work for your app either.
Don't forget, you're running a fair number of emulation layers in there, so it's not really representative of the speed of things on real devices.
If you want the latest features, go for the git version. I would, however recommend to go for the Diablo edition for now as the Fremantle one is pretty fluid - unless you need specific Fremantle functionality. The base Qt version in both is the same.