Are you talking about the SiteAdvisor browser add-on blocking websites? If so which website? Also are we talking consumer products or Enterprise.
If not, which product?
I will move this topic to where it will get help when you answer.
No we have inventory software that restaurants use and run from their computer, i have seen it on the standard McAfee Total Protection as well as one that was just called mcafee oas. It is not tied to website access (our software does speak to the web and transfer files back and forth) but rather as our software tries to access different files on the machine mcafee causes issues with the ability to read/write to our files which is preventing certain functions of our software from running properly (this is a brutally broad answer as I mentioned im not the programmer of the software).
If this was false detection you could still submit samples for diagnosis via avert Partners and Non-customers can submit samples via email to (firstname.lastname@example.org). (in zip file password "infected")
Unfortunately you sound like you are just having useability issues with the software due to blocks (eg access protection rules), in this case your designers will have to work out how to alter the configuration of McAfee enough to allow the software to work or what files and processes to except from Scanning/blocking etc. This would be something your company would do and distribute to your customers as advice when configuring your product.