Steps to reproduce

1) Open a new sheet with Firefox or IE9
2) On Sheet 1, add =sum(1,2) to cell C4
3) On Sheet 2, add =sum(3,4) to cell C4
4) On Sheet 1, select cell C4 first and click in the formula edit area on the formula bar, modify the formula, (e.g. replace 2 with 3)
5) While still in edit mode, switch to Sheet 2

Actual result

The C4 of Sheet2 now displays the formula from Sheet 1. If you try to click and edit, you are actually editing a cell in sheet2.

Expected result

Just like chrome and Excel. Leave edit mode while selecting another sheet.

Debug information

• Chrome doesn't have such issue
• 3.8.1.FL.20150713 still has this issue.
• If have doubt reproducing steps, please watch the attached videos