Websites fail to load only on the first attempt

I’m having a problem that would seem to point to dns. On several windows clients on my network the first website request for any website (this can be intermittent) fails and two seconds later the second request will go through just fine.

What is confusing is this behavior doesn’t seem to change when I change DNS servers (either my server 2003 DC or using OpenDNS)

I’ve tried using a dns flush to remove the cache but I’ve had no success so far.

Thanks in advance for any help