Pocket pairs are a strange beast. People have bestowed upon them an almost mythical status, that I think exagerates (in most cases) their actual % chance of victory.
Against a full table of loose call stations, even pocket aces can't be expected to win the hand more often than it loses. When less players stay in to the end, smaller pairs aren't much help.
I think the issue here is that we view pocket pairs -- especially face pairs -- so highly (we're so excited to get them), that we tend to expect more from them than they can deliver. If a pocket pair is good it might win 55% of the time for you (for example), but to do that it still has to lose 45% of the time. Etc...
All we can do is bet them hard, scare drawers off the pot, hope they hold up, but fold when you're beat...
I know what you mean, though, it sucks sometimes. According to Card Tracker, AA is one of my lowest % victory hands on the showdown, and I thought I knew when to fold them!!