Forums Bug Reports Line marker bug

Using version 6.21, I'm seeing a bug with the line marker. The marker is not always reset.

Open two connections and join the same channel on both. Tile the channel windows, use on window to write text and the other to show the bug.
Type text then focus the other window to reset the marker's position, go back to type more text.
You'll see that if nothing comes in front of the area used to display the channel conversation (this does not include the nick list, the editbox, and the window's borders), and if you don't use the scrollbar (which should not be necessary if the line is still visible), the position of the line marker will not be reset.

Expand the "typing" window to overlap the "channel area" of the other (one pixel is enough), and the bug is gone.

I can't seem to reproduce this issue here. I run mIRC and make sure that "Line marker" is enabled in Options/Display/Options dialog. I open two connections to the same server and join the same channel on both. I horizontal tile all windows so none are overlapping. I then type several lines in the first channel which then appear in the second channel with the line marker above them. I switch to the second channel and type several lines, and the line marker appears in the first channel above these lines. If I then switch back and forth between channels and type more lines in each, the line marker is correctly reset each time.

Are you able to reproduce the issue consistently? Are you using any scripts that might affect the behaviour? Which version of Windows are you using?