Can someone help me with this wordpress error

[keysync]

I was editing default-widgets.php and saved it.
Now when I save something, or try to log out or whatever I get a white page. And this is filling up the error log just about as fast as I can clear it.
Any ideas?
I've checked for a space before the opening < and it's fine.
No idea what to do. I really don't want to start over...

PHP Warning: Cannot modify header information - headers already sent by (output started at /home4/mechank1/public_html/wp-includes/default-widgets.php:1) in /home4/mechank1/public_html/wp-includes/pluggable.php on line 866

[MrE]

Get a copy of the stock default-widgets.php and compare to your modified one and see what doesn't look right.

[keysync]

Perfect. I just uploaded a fresh copy and it works... 5 hours down the drain. But thanks man!

[Fletch XXX]

Sucks whwn this happens

[geirlur]

what about this error?
On some blogs I get a "0" in the archive listing, so it looks like this
November 2009
October 2009
0

anybody know how to get rid of it?