Some keys don't work when editing a cell

Hi dhtmlx Team,

in a current project I use dhtmlxGrid with the dataProcessor inside a module of a CMS.
Everything works fine except the fact that the keys “q”, “w” and “z” don’t work in the edit-inputs and edit-textareas (the upper-case letters work!). That CMS provides accesskeys, which are disabled. So that’s obviously not the cause. HTML-created inputs and textareas work as usual.

Maybe there’s a known bug or something…
Any ideas?

Cause of the problem detected…
It’s not dhtmlxGrid, an other component blocks that keys.