Try holding Shift + Ctrl while launching Premiere Pro; keep them depressed while the splash screen is up. It might take a little longer to open than normal. Once you get to the Welcome dialog, create a new project, open it, close it and Premiere Pro, and then relaunch (normally) again. Try one of your previous malfunctioning projects.
Thanks for the prompt response! However, this did not correct the issue.
Some additional info that I was trying to add to my original post (but was told that I did not have permission to edit that post??)...
The application log on this system has many entries for the following error:
Activation context generation failed for "c:\program files\Adobe\adobe premiere pro cs5\setuproyalty\resources\libraries\ARKEngine.dll". Dependent Assembly Microsoft.VC90.CRT,processorArchitecture="x86",type="win32",version="9.0.30729.1" could not be found. Please use sxstrace.exe for detailed diagnosis.
along with duplicate errors for these additional .dll files - ARKCmdFS.dl, ARKCmdDefrag.dll, ARKCmdCaps.dl
A quick gogle search suggests these errors are usually related to conflicting/incompatible versions of MS Visuall C++ runtimes on the system, but since I don't know if or what version of the C++ runtimes Premiere needs, I am not sure where to proceded to decide if that is or had anything to do with the issue I am having...