Proxy: No Outstanding Request

[rvw at i2k.com]

Running Radius 2.1.6.   I am proxying to the server x.x.x.x shown below
and I keep getting these
messages in radius.log

Mon Jun 30 14:02:08 2014 : Proxy: No outstanding request was found for
reply from host x.x.x.x port 1648 - ID 51
Mon Jun 30 14:02:10 2014 : Proxy: No outstanding request was found for
reply from host x.x.x.x port 1648 - ID 81
Mon Jun 30 14:02:17 2014 : Proxy: No outstanding request was found for
reply from host x.x.x.x port 1648 - ID 128

What causes this?  
How is it fixed?

Thanks,
RonVW