Problem is caused by guiSetInputEnabled, which shouldn't be used really (but the editor does).
This will fix it until the next guiSetInputEnabled:
guiSetInputMode( "no_binds_when_editing" )
acpanel resource does this to 'fix' the problem:
addEventHandler( "onClientRender", root,
function ()
guiSetInputMode( "no_binds_when_editing" )
end
)