Placing App On Network

I'm sure this is a common issue but I am unfamiliar with the resolution of it.

I developed a C#.NET app on my local drive but then copied it onto a network server.  Now I get security warnings.  The app will not run at all and I get the message:

An unhandled exception of type 'System.Security.SecurityException' occurred in mscorlib.dll

Additional information: Request for the permission of type System.Security.Permissions.FileIOPermission, mscorlib, Version=1.0.5000.0, Culture=neutral, PublicKeyToken=b77a5c561934e089 failed.

I read somewhere that this is a service pack issue but I upgraded my .NET framerwork service pack but this still has not resolved.  What should I do different?

Thanks,
cj