I recently had to put Debian testing (Squeeze) on an old Dell PowerEdge 1650 server. Here’s a little tip to save you some time if your ever in the same situation: upgrade the BIOS first! More here
Its kind of a long story but my original PE1650 was running BIOS A10 when it died due to memory slot failure. So I borrowed a friend’s unused PE1650 until I could get a “new” one on-site.