I thought I may have a comment on my blog from you about this, but I didn't! =P It works exactly like GetCommonManager and GetUserProfileByName in terms of the parameter it expects. The returned data set is much different, but I've never done it and gotten 0 results. I would ensure that the profile import is fresh and has pulled in all of that info. Didn't you have errors previously in your profile import regarding your DLs?