samba - Nov 2009 - can't replace existing file

Dear all

 I am facing a unique problem in my samba configuration from last few days.

When a user try to replace an existing file with another file which
have same name as existing file, it prompt error "access denied".
  Same things works sometimes and sometime generate error. I checked
permission and that user has all permission on share.

Kindly help me how can i overcome this error.

Thanks
Vishesh kumar

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