Mine started doing the same thing right after Firefox update as well . Very aggravating. If you double click on the object you can finally get it to merge. Hope its fixed soon.
Double clicking works but it is a pain, really slows me down. Also, double clicking on crystals uses them so you can't merge them. I have to click on the crystal, then click in an empty box then click on the crystal again to pick it up to merge it.
You can report a bug, but it is hard to get to and hard to figure out just exactly how to do it.
I'm having the same issues in Merge and Trizzle. When it comes to the crystals use the right side of the mouse to move them.
