[Plugin: WordPress SEO by Yoast] WORDPRESS SEO with ATAHUALPA THEME – HELP

Hi
To start I am on WordPress 3.0.4 with the Atahualpa 3.6.1 theme.

I installed and set up WordPress SEO by Yoast which seemed to go ok, bit involved but ok, when I came to load my site it wouldn’t load, just gets to the point of loading very slowly

I can get into my admin page only, have now deactivated the plugin and site is ok.
Also
1)
Forced rewrite of title script does not seem to work and I can’t see where to paste it.
2)
Where do you paste the breadcrumbs script within the Atahualpa 3.6.1 theme?

Anyone got any idea’s, all help welcome

Phil