I use 5.04, and no plugins or skins. There was an issue, at least for a while, with some unwantedware accompanying addons from the site. Out of general paranoia, I never used the vis plugins or any skins afterwards. (in retrospect, this was when my 466 Cel was still a perfectly good rig. It's probably safe now.
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There are numerous mentions of fixing memory leaks in the 'what's new' readme that mine installed with, and I haven't had any problems with it on this rig. I figure if it works on this box, it'll work on anything.
AMD Socket A XP2400+
Asus A7N8X-X mobo
1GB Crucial PC2700 DDR
PNY Nvid 6200 AGP w/128MB ram