Problem with resx-localization

Suddenly our .NET RESX localization stopped worked on our Win 2008 R2 server. It works locally on our development computers (Win7). Are there any known common problems that we can check?

We are using for example:

var cultureInfo =newCultureInfo("en-GB");

System.Threading.Thread.CurrentThread.CurrentCulture = cultureInfo;

System.Threading.Thread.CurrentThread.CurrentUICulture = cultureInfo;

...and justice for all