A headers already sent error usually means that there is some whitespace after the last
?>
Could you post your blogtimes code at http://paste.uni.cc then post the url here ?
http://paste.uni.cc/6939
I used the code from http://dev.wp-plugins.org/browser/blogtimes/trunk/
Soon as I activate the plugin it gives me those errors.
Just to say that I also had this problem and to solve it:
1. Deactivated the plugin
2. Edited the plugin to remove the whitespace after the final ?> in the plugin file
3. Reactivated the plugin.
Thanks podz