Document library => Open with Explorer ; shows empty folder

Greetings,

We have a document library on SharePoint 2010 (Ent. Edition); once we try to open it in windows explorer using a domain account from a machine which is connected with Domain; it opens successfully.

But when we try to open it on machine which is not on domain using domain account then it will open the folder but no contents will be shown; the message is shown as "The folder is empty"; although its not!

Any solutions...

Thanks,

Ahmed