Tablix headers not repeating in SSRS 2008

I have created a new report & add a table to it. When I select "Tablix Properties" and check on Columns Headers -> "Repeat Cheader columns on each page" the header columns do not repeat on each page. I also tried "Repeat header rows on each page". "Add page break before" seems to work ok. I am using VS 2008 9.0.30729.1 SP

I also tried deploying but it still does not work on the deployed version.

Interestingly, reports migrated from 2005 & unchanged seem to be ok.

Any ideas? Am I not setting soemthign up properly?