Odd problems

For awhile on my new system SL would run perfectly fine.
Lately though I'm having some odd issues, I have prims, even those right next to me randomly appearing and disappearing, sometimes in bulk. And anything I type takes forever to be displayed or registered on my screen.

Currently running a AMD Athlon 64 X2 6000+
EVGA Geforce 8800 GTS

And I have one other computer on the network I'm using.

I have seen non-scripted prims appearing VERY late nearby, too.

Of course it could always be a script that makes them disappear.