Can I use my wallet on different computers?
It is, with three provisos.


Never run the same wallet on more than one computer at a time.
Never run an older copy of a wallet when a newer version exists. If you send any funds, make sure to keep the newer copy of the wallet.
Make sure all client programs are linked to the same version of BerkeleyDB.


Overall, I think it's just not a good idea. The client software wasn't designed to cleanly handle the many things that can go wrong.