A bug with wordpress 2.7 on “sticky post function”

Example:
there are three posts on 3 category:
post one name:  google-2009  in    category: google
post two name:  yahoo-2009   in    category: yahoo
post three name: rest-2009   in    category: funny

and now i sticky post "google-2009".and at the home page(index.php)
 but when i use "in_category('google') || is_category('google')",
it's back "true" value,

next i sticky post "yahoo-2009".and at the home page(index.php)
i use "in_category('google') || is_category('google')",
it's back "fasle" value,
but when i use "in_category('yahoo') || is_category('yahoo')",
it's back "true" value,

the same as the post "rest-2009"

I think it’s bug need to be fixed.so i write it here.

and following I have another question: 

how to get 2 sticky posts at home-page ,if i have 3 sticky post.

thank you ! welcome to 2009.