I recently upgraded to the release candidate of Ubuntu 10.04. Since then, two problems have occurred and persisted:
The boot splash screen has reduced down to a black screen with random color, blocks, text and gibberish at the top
and the themes are broken, as in the light themes have check-boxes in menus the same color as the background, and the dark themes don't correctly change the font colors in the top menu.
On a side note, is there a need to upgrade from 10.04 RC to LTS?