I'm more or less new to Curse and although I had managed to get 2 addons working (Auctioneer and Suki Minimap Coords), after the lastest patch 3.0.2, none of them worked at all. So now I'm trying out new minimap and coord addons but even though I follow the directions exactly, there're not working at alll either. I have a Mac OSX 10.5.5 Intel Core 2 Duo and I cn use both Safari and Firefox browsers.
On Safari, I tried the automatic install and I was directed to a window that said "Safari can’t open “psyn://addonservice.curse.com/AddOnService.asmx/GetAddOn?pAddOnId=4922” because Mac OS X doesn’t recognize Internet addresses starting with “psyn:”.
On Firefox, when I tried automatic install, an alertbox popped up that said "Firefox doesn't know how to open this address, because the protocol (psyn) isn't associated with any program."

So I tried using the manual install and followed the directions exactly. I tried Cartographer and nothing showed up in WoW. I tried QuestHelper and nothing showed up.

The Addons button in the lower left corner of the character screen showed up but when I clicked on it, with both Cartographer and QuestHelper, it said "dependency missing" and I have no idea what that meant. 

So I downloaded CurseClient and now when I try to download something, like QuestHelper for example, it shows the download bar, downloading, but then a box pops up that says "Can't create file 'QuestHelper/QuestHelper/static_deDE.lua' (error 2: No such file or directory).

I tried to download it again and now there seems to be response whatsoever.

HELP! I'm extremely frustrated and have absolutely NO clue what to do!

I agree with CKgreg it sucks so much and i dont know wat to do about help!!!!

The mac version is currently lagging behind the PC version, but a new build should be ready shortly after the next major release of the client for PC.

While the fine folks here at Curse work on updating the CC for Mac, read this post about manual installs. Should cover just about every general question you can have.