How to enable mouse scroll wheel in Freezed Column Headings crosstab?

[abcuser]

Hi,
in Cognos 10.2.1 fixpack 6 in Report Studio:
1. I created a crosstab that has many rows.
2. Run report.
3. In Cognos Viewer use middle mouse scroll wheel to see the more data in crosstab report. Works fine.
4. Right click on crosstab and select "Freeze Column Headings".
5. Click somewhere inside crosstab and now use middle mouse scroll wheel - what happens? Nothing. Expected is to move crosstab data down to see more data in report, but middle mouse scroll wheel does not have any effect.

Is there any setting to enable this middle mouse scroll wheel when crosstab is in "frozen headings" mode?
Thanks