Reading pdf files

[k. jantzen]

Hello,

in general I do not have a problem reading a pdf file with either xpdf 
or documentviewer.

But once in a while I get a pdf file that they cannot read and then I 
have to go to Windows to open it.

What is so spectacular about these files that they cannot be read by the 
above mentioned programs? Is there another program that would read such 
a file?

Thanks for your help.
--

K.D.J.