Server unable to be pinged (it just has an "x" over the bars and keeps saying "pinging")

The server browser is completely unable to ping my server. It gets stuck at "pinging" and never goes any farther, however I am able to still connect to the server by double clicking it. It's obviously on and working because I've still been playing on it.

If this issue is unique to me, I'll reexamine my files and everything but this has been happening in several of the more recent 1.7 snapshots and now the release candidates.