For multilanguage forums, it is better to use already existing phrase, not hardcoded posts, so use:
HTML Code:
<li class="welcomelink">{vb:rawphrase welcome_x_link_y, {vb:raw bbuserinfo.username}, {vb:link member, {vb:raw bbuserinfo}}}(<a href="search.php?{vb:raw session.sessionurl}do=finduser&userid={vb:raw bbuserinfo.userid}&contenttype=vBForum_Post&showposts=1">{vb:raw bbuserinfo.posts} {vb:rawphrase posts}</a>)</li>