Thanks, I have seen this as well, across different versions of mIRC, although it happens so rarely that it has been impossible to reproduce. These buttons are drawn by the Windows MDI handler, so mIRC has no control over them. It looks like, in some situations, the MDI handler gets confused and ends up drawing two copies of the buttons in different themes in the menubar. It's quite bizarre. It may be that, in future versions of mIRC, I will have to implement my own MDI handler if the Windows implementation stops working correctly due to Microsoft no longer updating it.