Unable to load DLL 'myDLL.dll': The specified procedure could not be found. (Exception from HRESULT: 0x8007007F)

I have WCF service that call to function "init" from some dllwrapper.dll. When i call dllwrapper.init, i got the exception:

Unable to load DLL 'myDLL.dll': The specified procedure could not be found. 
(Exception from HRESULT: 0x8007007F)

when dllwrapper.dll try to import myDLL.dll. It happend to me only with WCF services. other service (console app) that call dllwrapper.init, dont get this exception. what can be the problem here? thanks