Visa credit card not being verified

It looks like I am in a long line of potential clients whose credit card cannot get verified through Visa.  I have spent several days with Visa and Suncoast Credit union, and the issue has nothing to do with either one. Everything points to the fact that the card is fine with both. That only leaves Dell. I cannot believe a company the size of Dell has a concern like this.  I need to order the computer and monitor on my corporate credit card, but the Dell site will not accept it

Michael S.