Problem with Multichip for PSOne

[Pegasus21]

I have a PSOne (PAL) with a Multichip ver 2.20 in it.

My problem is that after deleting some games from the cheats manager, I would get a black screen when I try to go into the cheats manager.

Everything else (Playing games, other menus on the Multichip menu) works fine.

Is there any way to reset the cheats manager memory or to solve it without reseting the memory?

Thanks.