error loading Dll File

I have an ASP .NET application, that uses a assembly that uses another Dll File.

I copied all dll to my \bin folder and in my local machine it works perfectly, but when I upload it to my hosting it gives me an error saying it cannot load load the Dll file.

I was checking some forums and I saw some topics discussing about the IUSR account permissions for IIS5, but don't know if that can be the problem.

If someone knows better abbout the this issue and could give me some help I would appreciate.

Tks