Hi Dave,
Unfortunately I have gotten some reports that there are some IE9 issues. I have it on my todo list to figure these out and fix them, but haven't gotten around to it. In the meantime, I suggest you try out the free "Sortable Fancybox Gallery" addon:
http://www.concrete5.org/marketplace/addons/sortable-fancybox-galle...

...as it contains most of the functionality (and uses the same display code and styles) as the Deluxe Gallery. If the free one works well enough for you then the Deluxe one will to -- and vice-versa.

Thanks for the inquiry.

-Jordan

I have been using it extensively in the last week in both IE9, IE8 and Chrome 12 and haven't found any issues yet. Of course that doesn't mean there are none, but so far so good.

Thanks guys, I'll try the free one and see if I have any issues.

FYI, all known IE8 and IE9 issues have been addressed in the most recent version of Deluxe Image Gallery (1.0.4)