Problem with SQL connection on Intermec Bar Code Scanner

I have SQL Server 2005 on Windows Server 2003. I have database with ERP software and connect with it without any problem using other computers. Everythink works fine. But I have also Intermec model CK3n1 with Windows Mobile 6.1 Classic. I can't connect to this database. There was a time where it works perfectly but then we had long brake. Unfortunatlly we can't connect with database from Intermec device. One of company made for us special software which can connect with ERP program and connect to database but they can't help us. I can ping server from Intermec, I can login into to ERP software but it can't read database. Software on Intermec should show all documents inside the ERP but it shows nothing. When I close program I have an error: "Problem with database connection". Even when I disable firewall on Server it doesn't help.