PB 11.5, Win7 64 - Language changes when text focus changes

Hi,

I came across a situation I have never encounter before.

One of our clients is facing the following issue:

Their PC are running Windows 7 64 bit and have two language EN (English) Greek (EL)

Whenever the user goes from one textbox to another, it reverts the language in the default one!

So an example...imagine a logon screen...the username is in Greek, the user enters it, and when the user goes to the password tab the language reverts to English.

This is very frustrating for the user. I have not see something like that in any of our 100+ installations (build with PB 11.5). The problem is that I cannot prove it is a Windows issue because I did the same with the logon screen of SQL Management Studio and the language was retained...

Any clues?

Thanx