Hi Mark, please ignore the spam message promoting an unofficial phone number.

Mark said

When I have 5-6 tabs open on a single window, I am no longer able to move tabs with my mouse.

Do you mean you cannot slide them left-right along the tab bar?

At the point where the problem begins, is the bar "overflowing" -- this is indicated by scroll buttons that appear at the left and right of the tabs -- or is there still space for more tabs?

1. Yes, I cannot move the tabs left-right along the tab bar.

2. No. And my tab bar doesn't "overflow" and never shows scroll bar no matter how many tabs I open.

And lo and behold, the problem has now disappeared.

Thanks.