745,
If you've read the dozens of posts citing issues with the 1.11 and 1.12 software you've probably figured out your problem by now. Unfortunately as the feature notes indicated for the 'upgraded' firmware, you can't go back to the v1.01 that your router probably shipped with and that probably worked just fine.
If you haven't read the posts, do so. There are some workarounds (mostly disabling DNS) that seem to fix the frequent signal drops you've described. You'll find in your reading that the 825 is really a pretty good router. It's just the upgraded firmware that seems to have issues.
Cheers