I cannot add rows to a Sharepoint list when editing in Excel

[kepa88]

When I open the Sharepoint v3.0 list in Excel 2003 SP3 (export to
Expreadsheet) I get the following error:

"This list is linked to a Sharepoint document library. You may edit existing
document rows, but you may not add or insert additional records, or commit
changes to folder information".

I have Full Control over this list and the rest of people with same rights
than me can add rows with no problem.

This error came up after installing a Microsoft Hotfix (KB952608) as all the
cells appeared as read-only before installing the fix.

Thanks!