Error message in WordPress 2.7 RC1

Hello

I updated my blog to 2.7 RC1 yesterday (the new dashboard is very good), but sometimes i have the following error (or simillar):

Fatal error: Allowed memory size of 16777216 bytes exhausted (tried to allocate 7680 bytes) in /home/webcindario/o/b/oblogdeleo/wp-includes/pluggable.php on line 834

If I update the page one or two times, works fine.

My blog is http://oblogdeleo.webcindario.com/

Note: Sorry, my english is very, very bad, I’m from Spain

Thanks