It’s one of Corel’s more obscure bugs. Word Perfect x4 will fail when importing a JPEG file if a previous export (of anything) to PDF has been done.
This supposedly only happens on multi-core processors, but that includes most all of them these days. Word has it that Corel won’t fix this in x4 but that it is fixed in x5. I run x4 in Windows 7 64 bit – even though Corel says it won’t run on W7 – and it works just fine apart from this bug.
The problem can be avoided by manually deleting a directory. This has to be done after each export to PDF. After making hidden files and folders visible, delete this directory:
C:Users<your username>\AppData\Roaming\Corel\WordPerfect Office X4\User Config
You won’t lose anything unless you have created your own “named settings”. Another way to skin this cat without making the hidden visible is to paste this into a command promt window or line (“cmd” or “run” in the start button search):
rd /s /q "%APPDATA%CorelWordPerfect Office X4User Config"
As always, YMMV, and do your own homework to confirm before trying anything I suggest here.