Error deleting pages in WP2.7

Although I get the error, the posts are actually deleted as their IDs no longer appear in the database.
I deleted another page and discovered that the numbers are corresponding to the number of the page I am deleting and the three previous (ie all) autosaved revisions.

I tried again with a test page, got the same error, but noticed an additional error at the bottom (this was possibly in the others and I missed it)
Warning: Cannot modify header information – headers already sent by (output started at /home/alter871/public_html/wp-includes/wp-db.php:517) in /home/alter871/public_html/wp-includes/pluggable.php on line 850

This might shed more light.

Now have found lots of entries for this error and am working my way thru them.
(Deleting rogue spaces at the start or end of the files mentioned.)
Don’t want to get flamed for conducting an insufficient search

Now the world can see my thought process at work……

I fiddled around with all of those file to no avail.
Then I decided to unload all of the plugins and the error went away.
I loaded the plugins again and the error came back.
By removing the plugins one at a time it turned out to be the Broken-Link-Checker plugin that was causing the problem. This is not a 100% satisfactory answer though because another of my sites uses this plugin without error.

I concur. I was getting the same error messages. De-activated Broken Link Checker v0.4.10 and deleting works without error messages.