http://bugs.winehq.org/show_bug.cgi?id=20205
--- Comment #2 from cnbiz850@sohu.com 2009-10-01 19:17:20 --- Further update.
I found it actually has to do with visual effect (on Ubuntu: System>Preference>Appearance>Visual Effects). On my old computer, I normally have the effect off, so it behaves like what I described on the first report -- tweaking winecfg can correct the problem. When I have the effect on, winecfg can not correct it, except that unchecking "allow window manager to control it" still can make it to maximize, but when restoring window manager control, it does not stay maximized anymore. This is confirmed on my new computer as well.