Problem posting large amounts of text on WordPress

I have the latest version of WordPress installed and I have problems posting large amounts of text within the single post. Large amount ~ 1 page of a Word document.
When I hit the publish button, I get the following error message:

404 - Not Found

Sorry, no posts matched your criteria.

And the URL in the adress bar is still: http://www.myblog.net/wp-admin/post.php

Have any of you ever had a similar problem? If you had faced it and found out how to handle it, please post here. Thank you!

Are you cutting and pasting directly for Word? Are there a lot of images in the document?

If it's just text, I'd try cutting and pasting to a plain text editor like Notepad first, then cutting & pasting from Notepad to WordPress.

I've done this on several of my blogs with multiple pages of content before with no problem.

Another thing I just thought of, how many services are you pinging? The only time I have a problem like you described is either with a crappy host of if I have 15 or more services I try to ping to.

TxDon