CCleaner 2.34.1200. System details shown in CCleaner screenshots.
Still getting the odd horizontal scroll bar issue. Easier to describe with screenshots:
Before maximizing. No horizontal scroll bar:
After maximising and moving the "size" column to the right:
Restore down and I now have a horizontal scroll bar:
The problem is, the scroll bar disappears again when CCleaner is closed down and re-launched. The column change isn't retained.
I wouldn't mind this issue so much if each item could be fully displayed with a "mouse over", but of course CCleaner doesn't have a "mouse over" feature.