Excel 2003 sp2 autosum gets inserted automatically

[David Stirling]

to duplicate this problem follow these steps:
select F1 and click autosum button - use mouse to select e1-a1 - press enter
select F2 and click autosum button - use mouse to select e2-a2 - press enter
skip F3
select F4 and click autosum button - use mouse to select e4-a4 - press enter
select F5 and click autosum button - use mouse to select e5-a5 - press enter
skip F6
lastly select F7 and click autosum button - use mouse to select e7-a7 -
press enter.
Notice that there are no totals in cells F3 and F6

enter the number 1 in C1, C2, C3, C4, C5, C6 and C7, now notice that there
is a autosum that got inserted into F6

any ideas? i have removed autocorrect options.