iPod freezing in Cover Flow

Since I updated my iPod Touch 4G to iOS 5, I've been facing a really frustrating issue with Cover Flow. When I'm flipping through cover art, whether I'm playing a song or not, it will usually freeze for a second and return to the home screen (sometimes to the Mail welcome screen).

I still have no confirmation of what might be causing this to occur. I figured it might be an issue with the iPod's limited RAM. I use high resolution images for my album art and these sometimes take a second or two to display. I'm currently using my device for music only (32.7 GB) and have 24.7 GB free. I've tried restoring my iPod to its original condition and syncing only 20% of my music, but the problem persists. I'm thinking of restoring it again in case I have better luck a second time.

If anyone has encountered the same problem or has an idea of what's going on and how to fix it, I'd like to hear from you. Thanks in advance.

Have you tried restoring it to factory settings?

I have an iPhone 4 and an 80 GB iPod classic. Whenever either acts up, I restore it to factory settings...and that usually fixes the issue.

Just a quick update to deter anyone from having to reply. My brother pointed out to me a while back how to see the apps/programs that are currently running on the device and how to close them, I had way too many programs open without even knowing it! This was probably the cause of it's memory issues. So far the problem has been solved.