CTRL+SHFT+DOWN not working (but UP does)

[Ruts]

So oddly enough for me only one direction of the CRTL-SFTT-(arrow) isn't working for me.

I can CTRL SHIIFT UP/LEFT/RIGHT but not down.

I can CTRL-DOWN, but not CTRL SHIFT DOWN.

Scroll Lock is off, the Transition Nav Keys is unchecked .... any ideas ?

 

[RoryA]

Does anything happen with Ctrl+Shift+Down? How about if you start Excel in Safe Mode?

 

[Ruts]

nothing happens at all with CTRL-SHIFT-DOWN, cursor does not move, active cell remains active.
Safe Mode seems to make no difference.
No difference if I am in a previously saved or a new workbook either.

 

[RoryA]

I assume the Down arrow key does work otherwise? Do you have any other software that might be interfering?

 

[Ruts]

Down works fine, even Ctrl Down works, then I can ctrl-shift-up.

Nothing else program wise is running and I have no add-ins outside standard ms add-ins (analysis toolkit etc)