Yes, I had the same problem in Bridge CS3. Very frustrating. It didn't happen at first then I think once I had lot of stuff in Bridge.. the issue started to occur.
A few suggestions:
1) Move to lightroom 2. Not sure if btrenkel is referring to lightroom 1 or 2 but so far I have not encountered this in LR2.
2) Download and install the Adobe PS CS4 trial which will install Bridge CS4. If I am not wrong, Bridge CS4 will remain usable even after the PS CS4 trial expires. Someone correct me if I am wrong on this.