"The page that pops up has a HarborTouch logo on it and says to call their tech support if I need this domain to be unblocked to us my POS."
This is not how an OpenDNS block page would look like. I'm afraid your issue has nothing to do with OpenDNS but could be Adware or Malware on your computer.
To confirm this not being related to OpenDNS, copy & paste the complete plain text output of the following diagnostic command to here:
nslookup -type=txt debug.opendns.com.
You may also want to post a screen shot if this reoccurs.