It doesn't work with X-Terminal... Well, it works but not as intended.
If one terminal is open, this wont switch to another task (i.e. a browser instance).
If there's two terminals open, it will switch between these two instances but not to another instances (i.e. a browser).
If you have the browser instance open it will switch ok to terminal but it will get stuck there, switching between itself (if it has only one x-terminal instance open, or between the number of x-terminal instances open at the time).

Anyways thanks a lot. We have ALT+TAB now .

EDIT: It also interferes with ANY textbox i.e. 'Conversations' (it just wont switch at all).-