This problem has something to do with compiz. I by default had compiz on, and I have this problem. Then I turned compiz off, and I was able to get the desired transparency. When I turned compiz back on, I could again get the transparency, so I can no longer reproduce the problem.
This problem has something to do with compiz. I by default had compiz on, and I have this problem. Then I turned compiz off, and I was able to get the desired transparency. When I turned compiz back on, I could again get the transparency, so I can no longer reproduce the problem.