I noticed the same problem. I don’t know if it had been there all along and I just hadn’t noticed, but I just upgraded to Buddypress 1.2.4. I’m also using the the BuddyPress Template Pack to create a custom theme. To work around the problem, I replaced:
<?php bp_user_link() ?>
with:
<?php bloginfo(‘url’) ?>/members/<?php bp_displayed_user_username() ?>