I can't drag my plug-ins to the FX bins anymore - they stop halfway through the destination. Also if I try to drag the corner of any of the tracks to open them up to see a larger view it's not grabbing a hold and staying a hold. Do I need a new mouse? Or have I screwed up the settings somehow? Or?

Some mice are indeed afraid of the FX bin and won't go that far.

Is your cat sitting somewhere near the bin?