I recently upgraded a Compaq Evo 510s from Hardy to Lucid. The first problem I encountered was instability running X-windows. The display would go black with a few white stripes.
It seems I wasn't alone - other Lucid users with Intel's integrated graphics chip were reporting similar problems. Several solutions have been proposed. I went with the simplest - switching to the VESA video driver. This solves the problem at the expense of losing hardware accelerated graphics. However, as the Evo is essentially a thin-client this wasn't a problem.