Kenmichi, can you please list the PitBull modules you use? Nobody else has reported issues with frame deletion.
Also, I have no idea why you're getting that DogTag error. Update fully, and if you still have problems, try disabling your other addons. Let us know if you still have problems, or find a conflict with another addon.
Nothing else, except what's included in the Pitbull package itself.
I'm updating Pitbull and DogTags again as I type this, so I'll let you know how that goes.
 Now FuBar isn't working, and according to my UI Pitbull isn't even installed. /Pitbull just gives me the command error, and I've ben reverted back to the blizzard unit frames.
[edit2] Okay, I deleted all mods related to LibRock and that did the trick, Pitbull is back to normal. Well, almost. This error I get when I log in.
Error occured in: Global
Message: ...PitBull\libs\LibDogTag-Unit-3.0\Categories\Auras.lua line 212:
Bad argument #3 to `AddTag'. "HasAura" already registered
...e\AddOns\PitBull\libs\LibDogTag-Unit-3.0\Cleanup.lua:34: in main chunk
It obviously has something to do with a miscommunication between Dog Tags and Pitbull and Cowtip, which is the problem everyone else is seeming to have. But it's funny because I'm not experiencing the same problem as those reports, just getting the error. I guess now I just sit and wait for the official fixes for both.