I don't know of anything nasty off-hand, but then I also don't have 10.5 around (and 10.8 is in-bound), and it's a good bet that the server configurations I work with will differ from what you're running. In other words, "try it."
On your quest for issues, I'd dig through the archives of the Mac Enterprise mailing list and see what turns up.
There's a veritable goldmine of server-related information available in the archives over there. If you're operating OS X Server, that list the largest-volume resource for server-related discussions I've encountered, and the most technically-detailed discussions.