WHY: Jump to other cell when First char entered is upper case (2007)

[Poul Nielsen]

When I start entering text in a cell
(without selecting "Insert ..." first)
AND
the first character is in uppercase.
THEN
The active cell (as highlighted on the axis e.g. "A" and "11") moves
to the next empty cell or back to A1 and the character entered is lost.

This does not apply for the following letters.
E
ADF
CB

I have been unable to find any help anywhere ? so what have I done ?

/poul

Office Ultima
Excel Office 2007 (12.0.6300.5000) SP1 MSO (12.0.6213.1000)