I'm frequently seeing this problem: when going from a maximized view to a regular view ("restore") the window seems to be about twice the size of the screen. It seems like the upper left hand corner of the window is correctly anchored (ie. it is where I left it) but the rest of the MC extends offscreen down and to the right. I think Cascius is having the same problem.
Deleting the FramePos registry entry fixes this (once) but it keeps happening. I can grab the window edges to resize as well.
I run full screen visualizations at a resolution (800x600) that is different from the desktop (1280x768), and I notice that funny things happen during the transition - ie. the Windows taskbar is momentarily drawn in the middle of the screen.
Media Center Registered 10.0.122 -- C:\Program Files\J River\Media Center\
Microsoft Windows XP 5.1 Service Pack 1 (Build 2600)
Intel Pentium 4 2593 MHz MMX / Memory: Total - 1047 MB, Free - 680 MB
Internet Explorer: 6.0.2800.1106 / ComCtl32.dll: 5.82 (xpsp1.020828-1920) / Shlwapi.dll: 6.00.2800.1400 / Shell32.dll: 6.00.2800.1233 (xpsp2.030604-1804) / wnaspi32.dll: 4.71 (0002) , ASPI for Win32 (95/NT) DLL, Copyright © 1989-2002 Adaptec, Inc. / Aspi32.sys: 4.71 (0002)
Ripping / Drive D: Mode:Normal Type:Auto Speed:Max
Digital playback: Yes / Use YADB: No / Get cover art: No / Calc replay gain: Yes / Copy volume: 32767
Eject after ripping: No / Play sound after ripping: No
Burning / Drive D: PLEXTOR DVDR PX-708A Addr: 1:0:0 Speed:40 MaxSpeed:40 BurnProof:Yes
Test mode: No / Eject after writing: Yes / Direct decoding: Yes / Write CD-Text: Yes
Use playback settings: No / Normalization: None