I'm running iPhone 3.0, and I've had troubles with both the lite and regular versions of VV2 as well as Virtual Families Lite (don't have the full version yet).
Rebooting fixes it, but I'm rebooting it at least 2-3x a day, since I often go in and check on my little people throughout the day at work on my breaks. It gets really annoying, especially as it turns a quick check into something that takes a lot longer.
ETA: Here are some more details that might help with debugging:
iPhone 3G 16GB
Latest firmware 3.0.1
Latest carrier settings (O2 in the UK) - don't know if this makes a difference
9 pages of apps, 9th page not filled (yet)
I had no troubles with Fish Tycoon, but I haven't played it since I upgraded to 3.0.
Edited by lilitu93 (08/18/09 09:18 PM)