I’ve not come across any issues like this one yet. Can you tell me when it’s freezing up? Is it at startup, or when opening a file, or using a filter, or maybe when using the flood fill tool?
And of course, what are the stats on the image you’re using (if the freezes occur when opening an image)? If you press the ‘v’ key twice, a little info palette will appear with a bunch of information about the image. A little copy to clipboard icon at the bottom will copy all that, and if you can copy and paste that into here, that would be super helpful.
I do have a small suspicion though that maybe something wonky is going on with the GPU. I’m curious if a quick restart of your Mac clears the problem up? (This is to basically reset the driver for the GPU, which is where I’m thinking some problems might be).