Strange Flash Lag Problem

I have built a small image gallery and everything works great. I have images that automatically change, much like a slideshow. However, after leaving my browser open all night to the flash slideshow, this morning I noticed that it was lagging . . . a lot. It would barely even change to the next image. However, once I did a refresh - it worked fine. So I let it sit and I watched it and after about 30 min it started to lag again. I doubt if anyone will sit there and watch the same 4 images for 30 minutes, but I’m just wondering if there is something I can do to fix this.

The problem was mainly with IE on the PC, but I noticed a slow down on the mac in Firefox and Safari as well after a period of time. I’m calling the images through in XML too (I’m not sure if that has anything to do with it). The other thing I made sure of, was that I had bitmap caching turned off for the emptyMC calling in the images from the XML. One other thing that I can only think of, is that I followed the advice in the forums for solving caching problems within Flash by using the:

thisLoader.loadMovie(data[num].path + "?uniq=" + myIdentifier);

If someone could help me fix this lag probelm, I’d very much appreciate it.