[imp] Composition and PDF attachments

[cjdl01]

I'm using Imp 5.0.15 with Horde 4.0.12.

I am a linux guy, so I do 99% of my work on linux boxes.  As part of  
my work, I send a lot of invoices out to customers in pdf format.

I am using Mozilla firefox 7.0.1, and Adobe Reader 9.4.2 with the  
firefox plugin on a gentoo box current as of yesterday.  It works fine  
normally, but for some reason, when attaching a PDF to an email and  
clicking on the link (name of the attachment) to verify the document,  
it always opens up a blank, white window.  There is a very long, ugly  
URL in the address bar of that window (probably going to a hashed temp  
file), but nothing renders.

Clicking the attachment name link does not even offer me to download  
or open in another program, it just opens that blank window.

This is going to slow my workflow down something fierce.  Is there  
anything I can do to fix this?

Thanks.

-Chris