Just tried this out (and Affdots for my destro lock).
Getting the following whenever I place a wild mushroom, in or out of combat, only triggers it once but if I dismiss the error the next mushroom will trigger it.
Code:
Message: AffDotsDruid\AffDotsDruid-1.03.lua:219: attempt to index global "saGUID" (a nil value)
Time: 09/09/13 16:01:49
Count: 29
Stack: Interface\AddOns\AffDotsDruid\AffDotsDruid.lua:219: in function `?'
...ots\Libs\CallbackHandler-1.0\CallbackHandler-1.0.lua:146: in function <...ots\Libs\CallbackHandler-1.0\CallbackHandler-1.0.lua:146>
[string "safecall Dispatcher[15]"]:4: in function <[string "safecall Dispatcher[15]"]:4>
[C]: ?
[string "safecall Dispatcher[15]"]:13: in function `?'
...ots\Libs\CallbackHandler-1.0\CallbackHandler-1.0.lua:91: in function `Fire'
...ce\AddOns\AffDots\Libs\AceEvent-3.0\AceEvent-3.0.lua:120: in function <...ce\AddOns\AffDots\Libs\AceEvent-3.0\AceEvent-3.0.lua:119>
Locals: <none>