WordPress MU

Hello,
suddenly my rss2 feed doesnt work , there is an errror due to a white line at the beginning of the xml file. I've looked aroung the forum i've noticed someone had this problem but i couldnt find any solution.
I've tried to unistalle some plugins, I've traced back the rss file generation till do_feed_rss2 function where there is load_template(ABSPATH . WPINC . '/feed-rss2.php'); call. I've tried to put an echo before this call but the white line is brfore my echo. this function is used in add_action('do_feed_rss2', 'do_feed_rss2', 10, 1); but i'm not able to trace back in order to understand where this white line is produced. Who calls add_action and when?
any help is appreciated
paolo

It's always best to provide a link so we can see this please. (I believe the debugging script linked to in the readme file says something about that.)

Make sure there's no space lines within your wp-config.php file and nothing after the last ?> within that file.

here there is one link http://wildlifedirect.org/blogAdmin/lionguardians/feed
it's strange because worked since 2 days ago. I didnt make any change in this section. I've checked the wp-config.php
never changed since months

thanks
Paolo

The blog has a blank line at the top as well.

I hate to say it but you've got a file somewhere with space at the end of it after the ?> bit somewhere. I'd start off by checking what files you;ve edited recently and go from there.

I'm trying to look to new lines in all modified files still nothing.
In the mean time i would like to reconstruct the flow when the rss feed is called, i'm trying to go back from feed-rss2.php which generates the feed, ust like a stack trace. I'm arrived back at add_action('do_feed_rss2', 'do_feed_rss2', 10, 1). do you know where and when this function is called?
thanks

Ok I've got it , it was a blank line before a <? tag in a php file of my theme.
thanks
Paolo

Oh the blank line could be at the top. Sorry about that.

Glad you got it working.