Okay So the IIS limits have been changed. That is one thing we have not tried before, so we will see if it make any difference for us now.
As far as firewalls. we have one and it is on the lowest setting there is...so it might as well not even be there, but because of the type of site we run we have to have some sort of firewall/security.
The logs that we have checked which are from "X-cart" the shopping cart software we run, that manages teh downloads that are being sent out... was giving us a time-out error.
We have since changed a few settings that pertain to X-cart and have seen improvement in the downloads.. which is what I mentioned earlier.. instead of no downloads goign through, we only have 3 out 5 going through.. which when we have 6 people trying to download (different files) isnt a good thing.
I really appreciate all the input.. we are willing to try anything at this point... downloads are what our shop is all about and if your customers dont get their downloads.. we dont get our money... :)