Can't open Acrobat Pro 9 with Photoshop cs5 open

Question

For some reason I can't open pdf files or even the Acrobat application while photoshop cs5 is open.  As soon as I shut it down I can open the file no problems.  I'm assuming it has something to do with how much memory photoshop is using, but I've never had this problem before with any previous versions.  Any suggestions would be greatly appreciated.
Cheers

Answer 1

I've noticed two ways it misfunctions
1) Photoshop is open
2) I try to open acrobat by either using the quick launch icon that has always worked in the past, or by opening a pdf file either in a folder or as a link on the web.  It will not open and offers no error message.  It merely 'dings' at me like when you try to click on something in a doc when you've got another window open and u need to press ok or cancel before you can do anything else.
or
1) I've already got acrobat open
2) I open photoshop ok
3) I go back to acrobat and try to do something like print and the program crashes and shuts down... no error message.
Opening at the original exe doesn't change anything.  Acrobat works fine when photoshop isn't open.