Tried to assign Tools > Customize > Insert > Insert Current Date as a task for the F10 key to do. It would not set. Attempted other key changes there for other unused F- keys, and nothing took. Looks like a bug to me.
First went to Ctrl+; and pressed Delete so Insert current date was not assigned to any key. Then went to examine the F-keys. I noticed F10 is greyed out just like F6 and F1. Apparently they are reserved and cannot be used. I could set Insert current date to F3 just fine. I'll set to INVALID as this blocking of F10 seems to be intentional. Win 7 Pro 64-bit Version: 5.1.0.0.alpha1+ Build ID: 80ec99db4325a439a8a3f1d420d0a80f8bf9c439 TinderBox: Win-x86@62-merge-TDF, Branch:MASTER, Time: 2015-06-16_00:00:20 Locale: fi-FI (fi_FI)