I'm looking for a tool that will give me the proper generated source including DOM changes made by AJAX requests for input into W3's validator. I've tried the following methods:

1. Web Developer Toolbar - Generates invalid source according to the doc-type (e.g. it removes the self closing portion of tags). Loses the doctype portion of the page.
2. Firebug - Fixes potential flaws in the source (e.g. unclosed tags). Also loses doctype portion of tags and injects the console which itself is invalid HTML.
3. IE Developer Toolbar - Generates invalid source according to the doc-type (e.g. it makes all tags uppercase, against XHTML spec).
4. Highlight + View Selection Source - Frequently difficult to get the entire page, also excludes doc-type.

Is there any program or add-on out there that will give me the exact current version of the source, without fixing or changing it in some way? So far, Firebug seems the best, but I worry it may fix some of my mistakes.

Solution

It turns out there is no exact solution to what I wanted as Justin explained. The best solution seems to be to validate the source inside of Firebug's console, even though it will contain some errors caused by Firebug. I'd also like to thank Forgotten Semicolon for explaining why "View Generated Source" doesn't match the actual source. If I could mark 2 best answers, I would.