My Mac mini (2009 2.0GHz, 2GB RAM, OSX 10.6.8) has started having spells of painful slowness. Mostly it's OK, other times it runs like molasses, especially when opening apps or rendering web pages. I use it as my HTPC so it has a permanently-connected 1TB external drive full of my media, and that drive is down to about 50GB of free space. Could that be causing the slowdown?