Not having a Mac, I can't test this behavior out on one.
Did IT give any reason why you shouldn't update to v3? It's been out quite a while now and I haven't seen any major trouble reports linked to v3 so I am wondering why they are insisting you not upgrade.
v3 doesn't have any bug fixes that I am aware of that would affect this behavior.
On the PC side this "feature" is buggy, if you are using Windows XP--so there's no real improvment available by switching platforms.
For More Information see: Limited Local File Access Through Web Viewer in Windows XP
This is one of many acknowledged bugs that can be found in the Known Bug List here in the Report an Issue section of the forum.
It can also be downloaded as a database file from: http://www.4shared.com/file/8orL8apk/FMP_Bugs.html
IT did explain why they don't want me to upgrade, but the discussion happened been several months ago and I don't remember the details.
Sound like the feature does work without problem on Win7 in the link. This might be good news for us if this feature does work like we need it to.
I have access to both XP and Win7 through VMWare, which might add additional complications. If it does, there's always boot camp.