I've been in discussion with Jeremiah about this and he's trying to track down the problem but apparently it's a bit sporratic as some packages make it through just fine, while others build but then seem to disappear off the face of the planet; my guess is that new packages go through, but updates to existing ones are being dropped/fail to move over properly. I'll bring it to his attention again, but he said there was a major overhaul/upgrade of the repos and autobuilder system scheduled soon (apparently right now everything runs off of one poor cludged together server with a ton of random and confusing scripts to make it all work, and soon Nokia's sponsoring/proving several new servers at which time the build/repo software is also going to be updated to make management much easier and eliminate a lot of the random issues that have been appearing lately).

In the mean time your best bet is to go directly to project Garage pages, where developers should also be posting compiled versions of their code. this is independent of the repositories/autobuilding system, so you shouldn't have any problems there. If there's a package that's not posted up, the garage page will also have emails/contact info for the package admins who should be able to compile/post their packages for you.