Right click on the window and set the option for "always on top".
We must be talking about different things. when in MC mega-me, with playing now as the current mode, with the cover art showing above the track listings, right clicking on the cover art image does not provide me with a menu offering "always on top".
Media Center Registered 9.1.219 -- C:\Program Files\Media Jukebox\
Microsoft Windows XP Workstation 5.1 Service Pack 1 (Build 2600)
Intel Pentium 4 2516 MHz MMX / Memory: Total - 1048 MB, Free - 649 MB
Internet Explorer: 6.0.2800.1106 / ComCtl32.dll: 5.82 (xpsp1.020828-1920) / Shlwapi.dll: 6.00.2800.1106 (xpsp1.020828-1920) / Shell32.dll: 6.00.2800.1145 (xpsp2.021108-1929) / wnaspi32.dll: Internal ASPI Layer
Ripping / Drive K: Copy mode:ModeBurstBigBuffer CD Type:Auto Read speed:Max
Digital playback: Yes / Use YADB: Yes / Get cover art: No / Calc replay gain: No / Copy volume: 32767
Eject after ripping: Yes / Play sound after ripping: Yes Soundfile: chord.wav
Burning / Drive K: CDWRITER IDE5224 Addr: 1:0:0 Speed:32 MaxSpeed:52 BurnProof:Yes
Test mode: No / Eject after writing: Yes / Direct decoding: No / Write CD-Text: Yes
Use playback settings: No / Normalization: None