Photoshop doesn't, and can't, change the keyboard language.
Some other utility or system setting is doing that.
Probably your Avro software is set to change languages when alt-shift is pressed.
I already closed that program and tried.
I tried to change my keyboard with same keys (alt+shift) at different program, but they don't work.
it's only work at photoshop.
that's the problem.
It is a function of the operating system.
You can disable that shortcut by going to:
Control Panel> Regional and Language options(vista)>Keyboards and Languages tab>Change Keyboards button>Advanced Key Settings>Hotkeys for input languages> select Between input languages>press on Change Key Sequence>select "Not assigned" under Switch Input Language.