4.0 is looking good, thanks for the hard work.
One small problem though, reading a file last saved in 220.127.116.11 shows negative numbers in black font when they where formatted red.
New cells are correct and will highlight in red.
This is important to me so will need to re-install 18.104.22.168 if it cannot be solved.
P.S. If a cell within the formatted area is altered or deleted then formatted cells highlight red font. If saved and re-opened negative numbers are back to a black font.
New sheets in 4.0 act normally. I just tried a cut’n’paste from old to a new 4.0 sheet and when re-opened negative numbers are still back to a black font.
P.S.S. Seems to be the same problem as mariosv, so I have added my findings/comments to existing bug report.