Formulas containing double quote characters not handled correctly after editing

The spreadsheet control doesn't appear to handle editing formulas contain a double quote character correctly. I have done my testing of this issue using the DevExpress Spread Sheet FeaturesDemo project.
Steps to Reproduce

1. If you open the attached file XLS file in Microsoft Excel.

2. Notice that the result displayed in cell A1 is
     'GFA' and "FECA"

3. Click on A1 and you will see that its formula is:
     ="'GFA' and ""FECA"""

4. Open the XLS file with the FeaturesDemo.

5. Notice that A1 is displaying the correct result
     'GFA' and "FECA"

6. Click on A1 to display the formula in the "Cell text =" box, and notice that it displays the incorrect formula:
     ="'GFA' and """"FECA"""

7. Press F2 to edit the cell. Now press Escape to cancel the edit. Notice that the result displayed in A1 is now
     'GFA' and "FECA"

8. Click on A2 and then back on A1 to display the formula in the "Cell text =" box. Notice that the formula displayed is now:
     ="'GFA' and """"""""FECA"""

Expected Behaviour
 - In step 6, the formula displayed should match the formula displayed by Excel in step 3.
 - In step 7, pressing Escape after F2 should not result in any change to the formula or the result.