"Error reading directory" on Win XP

[john smith]

Greetings!

I've noticed that the following warning has appeared periodically
(twice in the last 45 hours) since I began running tor relay freeflow
(Windows XP Service Pack 2 [workstation] {terminal services, single
user} on the newly released Tor v0.2.0.21-rc(r13812).

[Warning] Error reading directory.

The error has occurred when I start Tor.

Regards,

john smith