This may have been fixed, since there are at least two versions newer than the one that I am using, but in case it isn't, here is a behavior that I found that I think is safely considered a bug. When adding or removing channels using the Song Properties menu item while on the Patterns tab, Modplug Tracker does not refresh properly. For example, when channels are added, the columns are visible from row 1 (0) to row r (where r is the quantity of rows in the pattern), but the channel headers are not visible. The same is true with channel subtraction. They disappear from the rows, but the channel headers are still visible. Also, when navigating to one of them that is off the screen, the view is not scrolled.