mac book air os x lion 10.7.2 windows network connection keep getting locked out

[arcolino]

hello, I have an end user with a mac air, running os x lion 10.7.2. I attached him to a network share on the windows network. he is the only one that when he clicks on the network share it sometimes connects and then locks him out. I check a/d and he is locked out each time. Is there a fix for this. other computer specs are processor 1.7 ghz intel core i5 4gigs memory. he is the only one having connection issues to that network share.