Newbie:gpdf-2.8.2-4.1 corrupts text output under FC4 2.6.12. xpdf-3.00-19 displays ok

[Clive at Rational <clive@xxxxxxxxxxxxxxxxxxxxxxxxxxx>]

Problem as described in title

Output in GPDF is about 4 lines display fine then
through rest of document to end, thin lines - some
dark, some faint - appear in place of text.

Xpdf displays all the text as readable content - even
though the font is a bit "blotchy".

Is this a known problem?

Thanks

Clive