I have experienced this problem playing 'gold' version 4.0.1.1461. Not using skins.
After running MM for a while it operates normally then, all of a sudden, can't minimize. When I close and reopen then it 'works' for a while.
FWIW, I normally hibernate my laptop for many days before I perform a restart.

I've been experiencing this problem while running 1462, 1465, and 1466 using the iMonkey skin (not sure it is the cause), which necessitated opening up task manager > Applications > "right click" the Mediamonkey instance > selecting Minimize.

Often times, when minimize does work the upper right portion of Mediamonkey looks like this:

[url=http://imgbox.com/aakyFto3][img]http://t.imgbox.com/aakyFto3.jpg[/img][/url]

Normally, it should look like this:
[url=http://imgbox.com/aahD2ZTq][img]http://t.imgbox.com/aahD2ZTq.jpg[/img][/url]

Then again, sometimes minimize won't work in the latter picture and the two pictures could be a quirk with the skin. Nonetheless, press the minimize button is not always a guarantee that Mediamonkey will minimize.

I am on a desktop (no hibernation), and I have this "failure to minimize" problem.

I believe it is something deep rooted in MM. Previously it would not stay minimized and open a window that had no minimize OR close buttons in the corner. This would change after closing and re-opening the app.

I reinstalled MM and now this failure to minimize problem...although closing and opening MM makes the problem go away, I'm sure it'll return.

It seems like it does happen more often after hibernating, but I hibernated last night and the minimize button works this morning. So I don't know..

MM won't minimize unless I hit the show desktop button (Vista). I'm not trying to get it to go to microplayer mode or the tray or anything. I'm just trying to make the window go away. If I click the taskbar or the minimize button on the window, nothing happens.

Also it seems to screw up Skyrim. Sometimes I switch to Firefox or something for hints or to check email and since the update, I sometimes can't switch back to Skyrim. Not a big deal but any ideas would be cool.

I think you may be right. I noticed that every once in a while the minimize button did work, but most of the time it didn't. I hibernate my computer multiple times each day, so it's possible I just didn't make the connection. I will try doing a restart and then hibernating and see if that causes the problem.

Any chance this happens after hibernate or remote desktop: http://www.mediamonkey.com/forum/viewtopic.php?f=7&t=62079&hilit=minimize

4.0.2.1462

Which version?

Well, this is a pretty inconvenient bug :) The minimize button does not do anything when I click it, but the maximize and close buttons do work. I think it worked when I first installed MM, but for at least the past week or so the minimize button has not worked.