Bevel Button behavior

I have a list box (datalistbox) with a column, that I can edit. I have a couple of buttons with predefined texts that should be transferred to the cell in which the cursor currently is. That works fine with standard buttons with the following code in the action event - mediksbutton() is a button area that contains the textblocks:

datalistbox.Cell(dataListbox.ListIndex,3) = dataListbox.Cell(dataListbox.ListIndex,3) +medikbuttons(index,1)

For UI purposes I wanted to do the same with bevelbuttons with the same code in their action event. Yet, the text does not show up in the listbox. Only if I put something like a messagebox before the code it would write the button’s text in den listbox cell.