Christian,

Here's an alternative for you. In the refresh of each button put this code;

LOCAL lcCheckBox
lcCheckBox = "THIS.Chk" + SUBSTR(This.Name,LEN(ALLTRIM(This.Name))-2)) + ".VALUE
This.Enabled = (&lcCheckBox = 1)

Then name the buttons and checkboxes as chk01 chk02 btn01, btn02 etc.. Once you've done this you can simply;

Thisform.refresh() to get everything enabled and disabled.