That's because there are no player-specific subforums outside of the installation ones.
If you suspect it has something to do with a unique piece of hardware in your player, you put it in the Hardware forum. If you think it's a problem with part of the rest of Rockbox, the "application" parts as it is, you put it in one of the forums most closely related. Because of the way Rockbox is constructed, very very little is player specific, and when things are, it's really a case like this (in which it's not player specific, it's specific to all the PortalPlayer chips) it's a single piece of hardware acting up that could be present in several players.
We've intentionally removed all player-specific forums (except for the install process because they'll each have unique install processes) to help people become aware of the fact that there are very, very few player-specific topics when discussion Rockbox, relative to the total number of subject.
Just one further thing: The forums aren't the right place for reporting bugs, they're just discussion forums. There's a proper place to report bugs.
Anyway, your problem is that the current version of Rockbox has issues on the PortalPlayer based hardware, due to a recent change. It's known about, and is being worked on. Keep an eye on the changelog on the front page of the site, or just wait a couple days using an older build until it's resolved.