The wireless driver is fucked over in the 10.5.2 update. The airport will drop the connection to the router after a few minutes of heavy use. It sometimes lasts as long as 30 minutes but then it drops the connection. Makes trying to download large files fucking frustrating. They better fix this one fast or Linux is going onto this iMac. Did they test the update at all? You would think this driver would have seen heavy use while testing.
It seems that Apple has corrected this in the last set of updates.