Handing out duplicate IP addresses

[Dave]

I thought I had this problem licked, but I still suffer from it.  Anyone 
know why FR 2.1.3 with sqlippool (mysql) might decide to hand out the 
same IP more than once while its processing more than one request at a time?

Wed Jan 14 22:05:59 2009 : Info: Allocated IP: 75.119.xxx,211 from 
IP-Pool   (did jarvis cli 00:18:D2:00:3E:63 port 449756 user pcollyer)
Wed Jan 14 22:05:59 2009 : Info: Allocated IP: 75.119.xxx.211 from 
IP-Pool   (did jarvis cli 00:18:D2:00:5B:0D port 449755 user jhogeterp)
Wed Jan 14 22:05:59 2009 : Info: Allocated IP: 75.119.xxx.211 from 
IP-Pool   (did jarvis cli 00:18:D2:00:2E:C1 port 449752 user mellerpoultry)

The requests all came in at the same time, to the second (among others), 
its like FR took 3 requests and looked at the database at the exact same 
time, saw it was an available IP and all those 3 requests assigned it.  
My NAS rejects two of the 3 because the IP is assigned, and Freeradius 
clears the IP from the ip-pool to be later distributed (even though its 
still in use)

Im open to any suggestions.  Its hard to debug!