Deactivated it to eliminate that as a possibility.
It may not be the cause, but Anti Virus applications often still cause interference when loaded, but disabled. That's why
we recommend uninstalling the application entirely, as a test, and not just disabling it.
Disk access issues, which manifest as the exact symptoms you describe, are
often caused by AV applications (even when disabled). If you think about what they're doing, it makes sense. With realtime AV enabled, all of MC's disk accesses for the file are first routed through the AV application, where it runs an algorithm to decide whether to let MC have access to the bit of data or not. All disk access is bottlenecked by the AV application. This happens
even when the application is disabled, because the low-level OS hooks are still there and running. It can't just load and unload them whenever it wants, which is why you basically always have to reboot to install or uninstall an AV application. Hopefully the vendor did a good job turning itself off "quickly" but... This can vary, and change over time as it interacts with AV vendor definitions updates, and your hardware (as disks fill up, and OS patches are applied).
As I said at the outset, it might
not be that, but I'd suggest it is the "most likely candidate" and it is worth ruling in or out (since doing so is relatively simple).
I also suggest you review the Disks and Locations sections of the Troubleshooting Guide, as those sub-pages contain
many suggestions for issues just like this:
http://wiki.jriver.com/index.php/Troubleshooting_Guide#Disks_and_LocationsHope this helps.