trying to add source but get lock settings??

Hi Guys,

Ive decided it was time to ditch boxee and get my hands dirty with xbmc! I have a Acer Revo r3610 that runs Win7, so i partition the drive and went ahead and installed XBMCubuntu. But the issue im having is trying to add sources. I have a Win7 pc that i am trying to stream to XBMCunbuntu on my Acer Revo, i go to system/file manager/add source/browse/smb/workgroup/Desktop PC(my pc) and i can add anything from my C: drive no problem but when i try to add anything from my D: drive it comes up with "Lock Settings" and asks me to enter a username and password

Can anyone help me with this?

Thanks