Windows 7 - Mapping from xp to win 7 drive problems :(

Im going to blow my brains out eventually but before that happens I hope someone can help me fix this nightmare. Here are the details:

Trying to map a windows 7 drive to xp via network switch and Ethernet. I've given the 7 machine a static IP of 10.10.10.10 and the xp machine 10.10.10.11.

From the xp machine: type \\10.10.10.10 and get credentials box. Insert user name and password and it connects immediately and shows "users" folder...no problem. However, if I try \\10.10.10.10\C$ or any other drive and enter the same user name and password it changes the user name to "computer name"\"user name" and nothing happens. I CAN'T GET THIS TO WORK AFTER 6 DAYS!

from the 7 machine: type \\10.10.10.11 and connects without credentials needed. type \\10.10.10.11\c$ and get credentials box. put user name and password and immediately have access to that drive with no problems.

No matter what I try I cannot get to any drives on the windows 7 machine from the xp machine and its driving me crazy. It also will not work if I'm logged in with the same user name and password on each machine at the same time. Any help greatly appreciated!!

Not a single thing I could look at?? Anyone?

UPDATE: I finally got the xp machine to map a drive on windows 7!! I only had to turn OFF file and printer sharing and it connected straight away! \\10.10.10.10\c$ was successful!