[Plugin: WP-Paginate] Round in stead of square

there are some embedded styles (in header.php) which also contain this part:
#sidebarsearch div, .navigation a, .comment-nav a {border-radius:20px 20px 20px 20px; -moz-border-radius:20px 20px 20px 20px;}

i can’t see from the outside, where these are coming from – however, if you remove the .navigation a, from the above code, your pagenavi links should be square again (even in firefox)

you could try to overpower these styles, by adding this to the end of style.css of your theme:

.navigation a { border-radius:0!important; -moz-border-radius:0!important;}