Excel 2007 Shift-Page Down Selection

I have a new desktop computer running XP Pro, 2.4 ghz processor, and 1GB RAM.
I can open a new Excel 2007 document and attempt to select cells by holding
the shift and page down keys. It will pause for less than a second and then
stop selecting even though I still have the shift and page down keys pressed.
I've disabled all add-ins and run the office diagnostics. I've also
uninstalled office 2007 and reinstalled it with no luck. Office 2007 SP1 is
installed.

Hi Group

I use a template developed and added to since 1999. There is heaps of code
and it is all over the place.
When I updated the template to Office2007 I would save the file under the
days date and close. When I try to open the new file it will not open until
I exit Excel. On reopening Excel and attempting to open the file an
unreadable error message is diplayed. If I trust the source would I like
Excel to fix. OK

Then a repair box opens with the following dialogue:

"Removed Records: Sorting from /xl/worksheets/sheet3.xml part"

In no way is the function of the file impaired but I have no idea where I am
looking to find where the record may have been remove. Is it in the code or
on one of 4 sheets in the file.

Hope someone can assist as it is a pain.

Murph