It could be because of the add-on card, but it is more likely something to do with other software on your system pulling focus from the application. Also, make sure you are using the latest version of the software. It should not continue to do this forever, but should stop after 5 unsuccessful attempts. This makes me wonder if you are using the latest version. I'm not sure which OS version you are using, but you can try the Win7 version of the uploader software to see if it's any better on your system.
Also, if you have special Dell keyboard drivers installed, these may be interfering with things. Make sure you have the standard US 101-key Keyboard drivers installed to make sure the system is sending back the correct responses to the software. Dell's software and hardware seem to be more prone to causing these types of issues.