If you run vbSEO then you will need to edit the template "memberinfo_block_twitter"
Change:
Code:
template: '<div class="smallfont">"%text%" <a href="http://twitter.com/%user_screen_name%/statuses/%id%">%time%</a></div>'
to
Code:
template: '<div class="smallfont">"%text%" <a rel="novbseo" href="http://twitter.com/%user_screen_name%/statuses/%id%">%time%</a></div>'
This should fix the javascript error you get.
FYI if you add:
To any <a href="blah"> tag it will stop vbSEO from modifying the link.