Problem description: Bug with the function "negativ number in red"

Steps to reproduce:

1. Create a new document, in a cell write =5-9 so the result is negatif (-4) [It is working with all the negativ number of course]
2. Format the cell and active the option "negativ number in red" - the color of the result is now red
3. Save the document and re-open it
4. The result is still negativ but he is in black (the option "negativ number in red" is active).
Info 1. If a change is made that effect one result in the document, the results come back to red in this document.
Info 2. The bug doesn't effect a negativ number who is not calculated.

Have a nice day and thank to all the developer ;)

              
Operating System: Windows 7
Version: 4.0.0.3 rc
Last worked in: 3.6.5.2 release