I use LXDE on gentoo, and previously on ubuntu 9.10. If I use 64-bit packages (with both distribution) the pager app doesn't refresh correctly. Each click on the widget causes that some window disappear, and some reappear. I can't observe this on 32-bit systems, but the LXDE version is the same...
I try to find more info about this issue, but google doesn't give any relevant hit.
(Sorry for my english
)