ABD U4 - Strange behaviour II

Further strange behaviour in U4

Today I wanted simply to switch of some displayed levels on the screen, so using the level display chose a level with no elements on it and then scrolled down the list of used levels to switch them off, but only about half of then switch off the remained remain highlighted blue (as usual), so individually select the levels shown as being displayed for them to switch off in the level display dialog but do not switch off on the screen.

So I had the situation that the level display list told me I had no used levels being displayed but the view window is displaying roughly half the levels.

Tried this on my second monitor screen and the same result.

Problem went away when I opened another drawing file and then went back to the first drawing

Anybody else had this strange behaviour?

Ian