It sounds as though you are creating your slideshow in the Elements Organizer and then porting it over to Premiere Elements.
This works great if, on the Output option screen, you select the option to Edit in Premiere Elements. It appears you're using the option to output it as a WMV file and then importing that WMV file into Premiere Elements.
A recent Microsoft update has messed up the way Premiere Elements reads WMV files, and that is what is causing the bug you're seeing. Here's Adobe's solution.
MicroSoft has issued an Update for Windows, that is causing problems with Displays. The following is from Talbot McInnis, who tracked down this problem, and offers a fix:
"MS bulliten MS13-057. Specifically, on XP kb2834904 and on windows 7 kb2803821 is causing a problem
.
For us, it occurs when decoding WMV9 files. Not all uses of WMV decoding are affected, but I confirmed that when connecting the WMV decode DLL to a sample grabber for RGB32 video, the frames arrive black on top, so that points directly to decoding internals of the WMV Decode dll.
You can uninstall these windows updates to resolve your problem."
There are several threads on the problem that this Update is causing on the PrE and PrPro Forums, so one can get more details. So far, there is not another fix from either MS, or Adobe.
Also, see this Adobe KB Article:
http://helpx.adobe.com/premiere-pro/kb/ ... mport-or.h tml