Editing a contact loads up extremely slow on firefox 3.x

When I view a contact and then click 'edit' (while on the summary tab), the next screen loads up extremely slowly on firefox 3.x (chromium and IE seem to cope Ok).

I fixed the problem by commenting out these lines in /templates/CRM/Contact/Form/Edit.tpl

cj('#selector tr:even').addClass('odd-row ');
cj('#selector tr:odd ').addClass('even-row');

Javascript is being used to iterate through all the groups and set the colour of alternating rows. This is fine as long as the Civi has only a small number of groups, but when you have hundreds the browser bogs down in a big way.

Ideally, the class of alternating rows would be set in PHP on the server, rather than using javascript on the client.