I believe, it's because the Combatlog-Eventhandling has been rewritten.
The old code was triggered by Tradeskill-Combatlog events, and the new code is triggered on EVERY combatlog event.
The problem with this is, the self:Update() isn't called in the enclosing if-block (and thus only called when necessary), instead it's called every time a combat log event fires.
So, the solution (in theory, not tested) could be to move the self:Update() into the if-block.
SkillsPlusFu, lines 336 to 338:
[2008/05/20 01:22:39-1954-x1]: FuBar_SkillsPlusFu-2.4.4\SkillsPlusFu.lua:49: AceConsole-2.0: args.frame4: "desc" must be a string
Ace2\AceLibrary\AceLibrary.lua:122: in function `error'
AceConsole-2.0-67789 (Ace2):2354: in function `RegisterChatCommand'
FuBar_SkillsPlusFu-2.4.4\SkillsPlusFu.lua:49: in main chunk