refused query on non-query socket

[MJ]

We are an ISP and using Bind 8.2.2-P5 on Solaris 8. Since long time we are getting following error messages.
named[346]: [ID 295310 daemon.notice] refused query on non-query socket from [212.x.x.x].53

We don't have any problem in DNS operations but few of our clients with MS Exchange servers some times complaints that they have intermittent DNS resolution problem which causes delays in their outgoing emails. usually they got timeout errors. I am afraid that is there any link in between this timeout complaints and the refused query error mention above.

I have read replies on this issue but still need more information that does it effect the DNS performance and how I can get rid of this error.

I hope I will get a positive response.

Many Thanks,
MJ