That's because the height it's too small. Combo box doesn't auto resize for each item, you must do it yourself.
Try this useful function: https://wiki.multitheftauto.com/wiki/Gu ... justHeight
function respawnWeed ( col )
if isElement ( col ) then
setElementData ( col, "isHarvested", 0 )
end
end
Then after:
harvestWeed ( thePlayer )
You can put:
setTimer ( respawnWeed, 300000, 1, source )