Thanks Terminator and CutterJohn - I've reset the dates and times, and everything I've downloaded since then has synced. I'll try the date-change trick next time I need a few extra days to finish a novel!
I wasn't able to get the "Run as Administrator" option from my mac when right clicking or launching ADE from Finder. I'll have to look into that, it sounds like a handy option, as I find the lack of options from within ADE frustrating!
KjellM, I'll give the update a try too, just to be on the safe side.
Thanks again for your notes.