asterisk users - Apr 2004 - Strange Warnings and dropped sip calls.

I've been getting this Warning message for a while now..

Apr 27 13:56:45 WARNING[1142106560]: chan_sip.c:5775 sipsock_read: Recv
error: Resource temporarily unavailable

and from what I can tell, this warning coinsides with a dropped call..
I'm running Cisco Gateways with Cisco ATA's (running 3.1 firmware) and I
am
doing Re-invites with NAT & STUN (and in some cases RTP aware routers)..
Can anyone give me any insight as to what this warning is about, and why
some of my calls might be dropping?

Thanks, Billy


             +--------------------------------------------------+
             | Billy Huddleston   Senior Systems Administrator  |
             | Net-Express                  http://www.nxs.net  |
             | 114 Sherway Rd.             Voice: 865-691-2011  |
             | Knoxville, TN  37922          Fax: 865-691-9894  |
             | billy@nxs.net                                    |
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