I was just looking at this again trying to fix it, this sort off tool popped in my mind to give it a try. It does lower the allocated memory of mediaportal when looking at taskmanager so I figured; it seems to do it's job.
Enable the virtual memory size column in Task Manager settings, it should show that MP VM allocation increases.
So this is no solution. Do you have a better one? And don't say do not use that much images, that skin, or that absolute folder path
Sorry, haven't yet read the thread thru, but might be that some skins are using unsupported ways to handle things like fan art.