Cannot access a secured shared folder in xp pro, from win 7 pro

hi, Computer A: windows Xp Pro Computer B: windows 7 pro secured shared folder in computer A with windows Xp Pro (documents$) i'm able to access the secured shared folder in all machines that running windows xp, and server 2003, with the credentials that i've created( username, password) But with computer B (win 7) i'm able to ping Computer B, but when i open the secured shared folder, it...