Multiband Compressor...

Hey I've been using the C3 Multiband Compressor, which is a free AU Plugin for a couple months.... Now all of a sudden it has stopped working....when i open a logic session where that plugin is being used it says cannot find... it is definately still in my plugins folder...and i tried deleting it and reinstalling it and the same thing keeps happening. im running 10.4.8 imac g5..... im not surebecause i hadnt used it in a coupe weeks and i might have had a software update happen or something could that be what it is? I absolutely LOVED this plugin for mastering my mixes, and now i can only use the vst version of it in Peak which i dont like cuzi can only do 1 plugin at a time there..... =\ any tips anyone? anyone have plugins stop working after software updates etc????
thanks
-anton