This started happening to me when I switched our media share from Windows Server to Windows 7.
I can confirm the HTPC is on the "high performance plan" with no drive spin down ever. Yet - MC still sometimes takes 5-7-10 seconds to actually access media on some days.
Well, it would be the disks on the media server that mattered, not the HTPC (at least, not as much). If
any application on windows requests a disk location that is sleeping or otherwise delayed, Windows blocks the application (hangs it) until the disk system responds.
This is not MC specific. It happens even to Windows components. As an example: If I delete a file off of my Users drive (which is allowed to sleep on my systems) and then wait a while for it to sleep again, and then lastly empty the Recycle Bin, then Windows Explorer hangs for a minute or so while the user's volume spins back up (and you can hear the drive spinning back up if you're close to the PC). It is fairly dumb, but that's just the way Windows works.
I don't
know that a disk delay is what is causing Park's issue, but that's what it sounds like, for sure.