Privoxy 3.0.16 ramdom DNS failures

Randomly and for no reason, various web sites either require multiple refreshes to display or browser close down and restart.. The Common point of failure with Dembut 1024 ands 8196 set seems to be DNS related... We have our own DNS servers, each located at different locations on the Campus.

Aug 10 12:08:38.420 00000930 Crunch: Blocked: http://rad.msn.com/ADSAdClient31.dll?GetAd=&PG=IMSCB2&AP=1007
Aug 10 12:08:53.428 000012f8 Crunch: Blocked: http://rad.msn.com/ADSAdClient31.dll?GetAd=&PG=IMSCB2&AP=1007
Aug 10 12:09:03.718 000019f8 Error: could not resolve hostname www.facebook.com
Aug 10 12:09:03.821 000019f8 Crunch: DNS failure: http://www.facebook.com/ajax/chat/buddy_list.php?__a=1
Aug 10 12:09:08.433 00001130 Crunch: Blocked: http://rad.msn.com/ADSAdClient31.dll?GetAd=&PG=IMSCB2&AP=1007
Aug 10 12:09:23.438 000017f8 Crunch: Blocked: http://rad.msn.com/ADSAdClient31.dll?GetAd=&PG=IMSCB2&AP=1007
Aug 10 12:09:23.835 00001748 Error: could not resolve hostname www.facebook.com
Aug 10 12:09:23.929 00001748 Crunch: DNS failure: http://www.facebook.com/ajax/chat/buddy_list.php?__a=1
Aug 10 12:09:38.446 00000320 Crunch: Blocked: http://rad.msn.com/ADSAdClient31.dll?GetAd=&PG=IMSCB2&AP=1007
Aug 10 12:09:43.944 00000bf8 Error: could not resolve hostname www.facebook.com
Aug 10 12:09:44.039 00000bf8 Crunch: DNS failure: http://www.facebook.com/ajax/chat/buddy_list.php?__a=1
Aug 10 12:09:53.457 00000bd8 Crunch: Blocked: http://rad.msn.com/ADSAdClient31.dll?GetAd=&PG=IMSCB2&AP=1007
Aug 10 12:10:04.058 00000a4c Error: could not resolve hostname www.facebook.com
Aug 10 12:10:04.152 00000a4c Crunch: DNS failure: http://www.facebook.com/ajax/chat/buddy_list.php?__a=1
Aug 10 12:10:08.457 00001564 Crunch: Blocked: http://rad.msn.com/ADSAdClient31.dll?GetAd=&PG=IMSCB2&AP=1007
Aug 10 12:10:23.464 000009e8 Crunch: Blocked: http://rad.msn.com/ADSAdClient31.dll?GetAd=&PG=IMSCB2&AP=1007
Aug 10 12:10:38.472 00000be0 Crunch: Blocked: http://rad.msn.com/ADSAdClient31.dll?GetAd=&PG=IMSCB2&AP=1007
Aug 10 12:10:53.476 00001128 Crunch: Blocked: http://rad.msn.com/ADSAdClient31.dll?GetAd=&PG=IMSCB2&AP=1007
Aug 10 12:11:08.487 000017f4 Crunch: Blocked: http://rad.msn.com/ADSAdClient31.dll?GetAd=&PG=IMSCB2&AP=1007
Aug 10 12:11:23.489 00001204 Crunch: Blocked: http://rad.msn.com/ADSAdClient31.dll?GetAd=&PG=IMSCB2&AP=1007

Action files petty much standard but even putting the failing sites in FRAGILE, we still have the same errors..
Seems to happen more on a Win7 64 bit but also happens on Vista 32 bit.

Thanks