Ed,
According to your "regional settings", your Excel might expect ';' (semicolon) as separator.
In this case, do it again by replacing your ',' entry by a ';'.
Otherwise, you can always edit (Notepad) your exported file with ',' separator and add a new top first line (to force the symbol used during the import process) stating :
SEP=,
It is a temp workaround, and I hope this might help.
Thanks, Eric