Which SEF extension are you using?
I checked this:
IEI visit your site and I click on "Strong momentum ahead" item. Then I get this URL:
/news/strong-momentum-ahead-542.html
When I click on TENDER BUZZ I get this URL:
/news/index.php?option=com_content&task=view&id=543
And the correct URL for this items should be this:
/index.php?option=com_content&task=view&id=543
FFI don´t know why with FF that doesn´t happen. Maybe because with IE the modules are reloaded and with FF doesn´t. Can you confirm that?