What's going on here? Crawl Errors

So I know Webmaster Tools isn't perfect, but I'm wondering why this happens..

http://www.goaliecrease.net/equipmen...hest-arms.html

- this link shows up in webmaster tools as a 404.

vbseo is in control of the url naming is it not?

the url has now changed too:

Reebok Pro Spec Pro Goalie Chest & Arm Protector

So why would we change the url anyways??? What is the good of it?

And can I fix or change this?

You should have MOVED the thread without leaving a re-direct. That let's it keep the same Id as originally posted, regardless of the forum it's in now. Deleting threads will ALWAYS result in the 'invalid thread id' message from Vb.

No one has deleted or moved threads.

Thread Id 1525 didn't turn into thread 1571 by itself....

Well yes it did. This is why I'm asking about it here.

It hasn't been moved or renamed, or anything.

vbseo doesn't alter thread ID's in any way. They are auto_incremented from mysql.

http://www.goaliecrease.net//showthread.php?t=1525

Doesn't exist in your database. it's been hard deleted. vbseo can't do anything to something that doesnt exist.

Interesting ok... I'll watch for further instances and keep track of what has been deleted. I only have one Moderator, and myself who have access to delete anything.

So we should never add a 30 day or permanent redirect when we move a thread? I always do this thinking that the structure of my URLs would be kept in index this way?

I suggest to NEVER leave a redirect as the current thread that becomes the redirect link keeps the original ID, and the new location gets a new ID and thus a new url. Anyone who has it bookmarked or linked will be forwarded via vbseo without the redirect.... and if people can't find their thread they posted, they can look it up by searching under their username/usercp.