Thanks Bigfoot - was able to get that fixed via phpmyadmin.
Also wanted to let you know that we found the problem, finally. I continued to troubleshoot from the Windows side and saw something about transfers failing when using wired ethernet vs not failing on wireless. My tower has a wireless nic so I unplugged the ethernet cable and transfers of large files to the HDA worked immediately. Same results with the other tower. We decided to change out the switch between the router and the towers and that was the problem - everything is working great now (it also solved a Netflix authentication problem we were having with the tv we have on the same switch
).
So it was on the computer side and a networking issue - I guess we just only saw it obviously with the large file transfers.
Thanks again for helping me troubleshoot Bigfoot