It *could* be the D-Link, but I think we've done some testing here with that hardware and haven't seen a problem. You might try downloading the latest firmware version for the 615 and see if that changes the behavior at all.

It could also be a problem with your computer blocking requests - maybe a software firewall or similar. We talk about that problem here:

http://www.nessoft.com/kb/27

Best wishes,
Pete