Adobe Acrobat - "There was an error opening this document. The file cannot be found"

Guys,

I have a virtual layer for Adobe Flash player, with an entry point of Internet Explorer. Outside of this, we have used Thinreg to associate pdf files with a Thinapp'd copy of the Adobe Acrobat Reader 7 (Using the allusers switch). What we find is that when trying to open pdf files from the internet, Acrobat Reader loads then presents the error "There was an error opening this document. The File cannot be found". If we save the file and open it works fine.

I'm positive this is a isolation issue somewhere in the Acrobat Reader layer config, but have not been able to track it down. Presumably the issue is the Acorbat layer is not looking outside of itself for the temporary internet folder which contains the pdf IE has cached?

Anyone come across something similar and has a fix?

Matt