Keyboard commands ignored

[DigiDurst]

I'm using AI Studio with an Epson 4870. I had some image quality issues which prompted me to read over some of the FAQs to find a solution. I found this:
"Workaround 2: only use optical scan resolutions. Set the "dpi"-slider in SilverFast to your desired resolution and click into the "dpi"-box at the right end of this slider. Now press the CTRL key on your keyboard and SilverFast displays the nearest optical scan resolution supported by your scanner. If the value in the entry box does not change, you selected a true optical resolution."

The keyboard shortcut for undo (command z) doesn't work either.

Basically it seems that all keyboard functions are ignored. Why is this? Please help - thanks!

[LSI_Magnussen]

The keyboard shortcuts have changed regarding that point and the FAQ is outdated there. To display the optical scan resolution you now have to press F5 instead of the CTRL key.
Undo should work however.

Best regards
Ralf