Instead of posts loading from my static-page site, I get Fatal Error (A 3.2/WP 2.3.3)

..."Undefined function is_front_page() in ....header.php

I am testing Atahualpa vsn 3.2 on WP vsn 2.3.3* on a functioning site with a static home page. The "other" theme is live right now...as I want people to look at my posts!!

When I test A, the (static page) home page, and all other pages work fine. Posts, however, give the fatal error. Help!

PS: Later versions of A won't load at all...dunno if this is my WP version, or plug-ins...and yes I did turn off all the plug-ins to see if they were causing the fatal error in 3.2...nope!

*Yes I will upgrade WP, then A, but because I also plan to change my theme (to A I love it...) am taking the moment to test A on my site http://yourfirstvisit.net first...I already run A on a different static page site http://WheretoFindHelp.org with a later version of both it and WP--works fine there...