Taskbar does not Auto-hide all the time Windows 7

I sometimes get the exact same problem, and I was intermittently getting it for years with XP prior to updating to Win 7, and I seem to remember getting it in 95/98 as well.  In any case, it's most definitely not a new issue in Windows.  More like one of the "classics."

I just noticed that it happens on my Windows 7 install when I disable Avast's shields so that I can play a game without anti-virus running in the background and slowing things down.  Once Avast is in "disabled" mode, you simply cannot hide the taskbar no matter what you do.  As soon as you re-enable Avast's realtime shields, the taskbar immediately cooperates again and automatically disappears.  That could be a potential solution for some out there -- when it happens again, try toggling settings on any apps that reside in the systray (or just exiting those apps) to see if the problem goes away.  There are other times when that is NOT the issue, though, and I'm still at a loss on a fix for those occurrences.

The Taskbar Slapper program someone linked in this thread does absolutely nothing for me on Win 7 x64 as far as I can tell.  It briefly appears in the systray area, but there are no tooltips and it poofs as soon as you point at it (meaning the program was already terminated and left a ghost icon behind in the systray).  Has no discernible effect on my taskbar autohide problems, though.

As far as the suggestion about "lock the taskbar" having anything at all to do with this problem, that's a typically clueless MS support answer.  While I admittedly have tried fiddling with that setting on more than one occasion over the years to try and fix the problem (my taskbar otherwise remains locked), I have never seen it have any effect whatsoever on the taskbar autohide feature, nor would I seriously expect it to have any effect since it's completely unrelated to that feature.  Aren't you MS people at all embarrassed to be giving completely useless, non-relevant and unhelpful answers like that?

On my system (see earlier posts) this problem seems to have gone away all by itself - I haven't a clue why this should have happened and I cannot connect it with any particular event, but it has not happened for some weeks now. Very strange.

Windows 7 Home Premium 32 Bit - Dell XPS420 3GB

I have the same problem.  Auto-hide is selected but it doesn't hide itself, whether I minimize windows or not.  It also does it when I'm looking at images with the "Windows Photo Viewer" and obstructs my view and access to the buttons in the program so its not limited to 3rd party programs.

This is exceedingly annoying and disruptive.  It may seem small but a bee is small but when it stings you it is at least annoying.  Wonder if Microsoft will actually fix this, but based upon this thread and other threads I've read on the matter and for other versions of Windows (I'm having this issue with Windows 7 Ultimate and may have had it with earlier versions too, I don't remember at this time) I'm guessing they may not do anything.