@ scotty: your ipdfv8 [md5: 257c1177b262a538f32b0b2c15238701] is not compatible with a "clean" 2.8. I tested it, your pdf viewer doesn't start.
[EDIT I] ok, correction. ipdfv8 opens the most of my pdf files. Perpaps there is manifest.xml incompability [doesn't like some lines in file or so].
[EDIT II] Yes, ipdfv8 doesn't like some manifest.xml. I have moved pdf out of directory with manifest.xml & scribble.irx & then ipdfv8 opened pdf file. One of my "problem" manifest.xml is attached.
[EDIT III] in~ & deinstallation scripts [ipdf8_2.8.zip]