Searching SMB server from Spotlight using IPTC keywords

We recently changed from Mac servers to SMB windows servers. All clients are OSX, but range from Snow Leopard to Mountain Lion (all are getting updated to Mountain Lion shortly; I'm personally on Mountain Lion). Since the server switch, we are no longer able to use Spotlight to search the SMB server with any regularity. Often no results found, but on occation it does find the items. Searching desktops is no problem, only the SMB server. We can still use the Find Any File application without any problem; not ideal at all but it works.

The main issue is that we have a large quantity of image files with IPTC keywords attached on the server. We used to be able to seach these keywords using spotlight, but not since the server change. The keywords are still searchable using Adobe Bridge, but that is not an option for every user on the server. Being able to search these keywords from any client is crucial, so any advice would be greatly appreciated.