Can not browse for multicast image file

[gdirubbio]

I have just built a new Tree NW6.5 with sp7 overlay and then I installed Zen 7 w/Sp1 and then ir3a. By default the tree is edir 8.8 and is now edir 8.8sp2 with the post sp2 patches.

I go into ConsoleOne and go to the properties of my server object and choose the zenworks imaging tab. Then I click add and type the name of my multicast session.
Under Master Image source - Use this image file as the master - the browse button is Greyed out. However if I choose - use this workstation as master - the browse button is not greyed out.

Any thoughts? I know others have seen this issue but I have yet to see a resolution to it.

Thanks
Greg