[DllImport("NetApi32.dll"... throws exception for first few times

[C# Programming]

Hi All,

am using [DllImport("NetApi32.dll", SetLastError = true, CharSet = CharSet.Unicode)] to access, save files to a network ********. The problem is File creation / save work fails for first few attempts and laters starts working fine. After a time interval say 5-6 hours again it fails first few time. Kindly help

Thanks in advance