c# and pvcs with ref parameters

Question

I have to call VM32VBWRAP.dll from c#. It is a library for manage pvcs from code. I am able for calling all methods which don't have any ref parameter. But I can't call methods with ref parameters.

I always get this error:

"Attempted to read or write protected memory. This is often an indication that other memory is corrupt." at System.StubHelpers.MngdNativeArrayMarshaler.ConvertContentsToManaged(IntPtr pMarshalState, Object& pManagedHome, IntPtr pNativeHome) at LibraryPanello.SourceControl.Pvcs.PvcsGetLockInfoVB(Int32 archiveType, String pathAndFileNameServer, String pathAndFileNameLocal, String usernameInPVCS, Byte[]& version, Byte[]& versionNew, Byte[]& usernameOutPVCS, Int16 info, Byte flag)

My declaration is:

[DllImport("VM32VBWRAP.dll", CharSet = CharSet.Ansi, SetLastError = true, 
           EntryPoint = "_wPvcsGetLockInfoVB@36")] 
static extern int PvcsGetLockInfoVB( 
    int archiveType, string pathAndFileNameServer, 
    string pathAndFileNameLocal, string usernameInPVCS,     
    [MarshalAs(UnmanagedType.LPArray, SizeConst = 64)] ref byte[] version, 
    [MarshalAs(UnmanagedType.LPArray, SizeConst = 64)] ref byte[] versionNew,  
    [MarshalAs(UnmanagedType.LPArray, SizeConst = 64)] ref byte[] usernameOutPVCS, 
   short info, byte flag );

Any idea????