Refresh issue displaying first page of PDF?

[Lee Fisher <fisher.lee@xxxxxxxxx>]

Hi everyone,
I am running apache HTTPD 2.2.14 on CentOS.
We have recently encountered an issue displaying some pdfs served by apache.
The first page will show up, but the text and content will not be visible.  If I scroll to page 2, the information will be visible and then scrolling back up shows the pdf as normal.  We can't figure out what is going on with these pdfs.

The ones I have seen so far are around 500k so it could be size related.
The documents have not exhibited this behavior when served from tomcat.
I don't see any information in error_log when the pdfs are accessed.
If I wget or save the documents to my desktop and then open them, they are fine.
Please let me know if you have any ideas of what could be going on.

This behavior has been observed in both IE and Firefox.

BAD pdf example one:
Shows nothing on page one until scrolling, however hidden text can be highlighted.
http://www.vishay.com/docs/20035/dcrcwe3.pdf

BAD pdf example two:
This one is not as consistent, and typically just displays the logo in the top right but nothing else
http://www.vishay.com/docs/68010/txxs.pdf

GOOD pdf example:
http://www.vishay.com/docs/85182/gsot05cl.pdf

Thanks for any clues what could be going on or who else we might ask.
Lee Fisher