GetURL, New Browser Window, PDF Problem

Has anyone had any problems with getting a PDF file to open in new browser window from Flash?

For example:

getURL("test.pdf","_blank");

I have a client using IE7 on XP that says they see a brief popup that disappears before it is rendered. No error message is received.

She is able to open a PDF from a plain html page

<a href="test.pdf" target="_blank">link</a>

Any ideas?

Should I try converting getURL’s to javascript calls?