Error while importing via Tools -> Import

Today I got a question regarding importing via the CRM Import tool (Menubar -> Tools -> Import). Only a small number of records would import, all the others would not. Even though the source seemed fine, they did throw this error:

0x80040328: Number of columns does not match the header row

This appears to be related to the source anyway. When you save an file in Excel 2003 as csv, it does the saving correct for the first records. Then after about 15 rows it starts to leave away the last splitter signs if the columns are empty! That does indeed end up in the error as shown above. The solution is to move one of the columns which does have data for all records in there, to the last column. Then again export the file to csv and do the import. You should now be able to import the records as expected.