Upload & Sell: Off
Are you by chance using windows 7 64 bit? I saw artifacting in the LR 4 beta on my 7 64 bit and I'm not sure it's been fixed, I opted out. Others have noticed it also, and mentioned it was only utilizing a single core on multi core processors. LR 3.6 64 bit worked pretty well for me on the same machine, but does some weird things from time to time. Requiring a shutdown and restart of the software. Haven't tried CS6. I was reading through the TOS on LR 3 and they don't even guarantee it to work on 64 bit. I had to read it twice before I believed it. I may try reinstalling it in 32 bit mode...ugh.
Don't get me wrong, I'm not dogging the software, it's great for what it is. Maybe I'll upgrade to 4.0 after a year and they patch it a few times. Then again, maybe not lol.