Downloading movie info dialog locks sometimes

When I start xbmc the NAS is scanned for new content.Sometimes the downloading progress bar locks. This is always at the very beginning, since the progress is at 1 or 2 percent. This happens in 5 to 10 percent of the cases. Only way to get rid of the dialog is to reset the apple tv2
Wired internet connection, NAS, and using mysql on the nas, no name substitution,using nfs, nightly 5 of Nov