Problem with ASP.NET and SqlAnywhere ado.net provider

Hi,

i developed an asp.net applciation on a Windows 7 computer, with visual studio 2010, using ado.net provider.After deploying on a Windows server 2008 64 bits, I get the following message :

Could not load file or assembly 'iAnywhere.Data.SQLAnywhere.v4.0, Version=12.0.1.36054, Culture=neutral, PublicKeyToken=f222fc4333e0d400' or one of its dependencies. The system cannot find the file specified.

I tried all docs and forums and could not get a solution...

Could anyone help to solve this issue ?

thanks in advance.