Help with TTT+ULX error

I am currently running a TTT server with ULX and some custom coded weapons, nothing else. Both ULX and the gmod server are up to date. After the map changes at the end of the round, I get a weird lua error.

L 11/17/2012 - 14:56:35: Lua Error: 
[ERROR] lua/includes/util.lua:184: attempt to index local 'object' (a function value)
  1. IsValid - lua/includes/util.lua:184
   2. UpdateHovered - lua/includes/modules/widget.lua:51
    3. PlayerTick - lua/includes/modules/widget.lua:91
     4. fn - lua/includes/modules/widget.lua:151
      5. unknown - addons/ulib/lua/ulib/shared/hook.lua:168

I would assume that this is caused by ulx’s ulib because of #5, but I cannot figure out what the problem is. Any help with what might be causing it, or how to fix it would be of help.