This happens to me in 12.10 as well. The background changes to light-grey "randomly" and then changes back to transparent after a while. I will try to see if there is a pattern in these changes not to call them random any more!
This happens to me in 12.10 as well. The background changes to light-grey "randomly" and then changes back to transparent after a while. I will try to see if there is a pattern in these changes not to call them random any more!