Just after 10 days of new Wordpress 1.5.1 been released, here comes Wordpress 1.5.1.1.

Improvements including the following:-

[General] RSS feed problem
[Optimization] ‘publish’ and ‘editpost’ have different flow in wp-admin/post.php
[General] quicktag “ins” and “del” format datetime attribute incorrectly
[Template] SQL Error with list_cats
[Administration] Broken page navigation links
[Administration] “nextpage” navigation on permalinks with no trailing slash fails
[Optimization] Feeds return 304 when no new posts have been made
[Administration] Call to undefined function: get_bloginfo function

You all can freely download it here.
As well as, take a look of more than 170 bugs been fixed since Wordpress 1.5.1.

Guide to upgrade is over here.

Enjoy.