I copied the generated source code (View Source -> View Generated Source in the Firefox Web Developer Toolbar) of Google’s Keyword Tool page to a new HTML file.
But, when I open this new file, some of the items looks stretched for some reason:

The original website looks like this:

I guess that Google create some elements and set various attributes using Javascript, but I copied the page after it has been generated. So, why is this difference?
UPDATE 1
The only JS/CSS file, which is not given as a full path, is:
<script language="javascript" src="/cues/cues.js">
I tried replace this with:
<script language="javascript">
Contents of '/cues/cues.js' here
</script>
but it didn’t help.
UPDATE 2
In the browser’s error console I found the following 2 errors:
Error: com_google_ads_apps_servers_cues_CuesRelease is not defined
Source File: https://adwords.google.com/cues/768DAEDDB2193AB5B05B9C6A01394D78.cache.js
Line: 1
Error: com_google_ads_apps_targetingideas_client_TargetingIdeas is not defined
Source File: https://adwords.google.com/o/Targeting/756D6AF3BB4DD4A68315E34F50C2BC7E.cache.js
Line: 1
Any ideas why these errors appear?
UPDATE 3
Apparently, the reason is that the DOCTYPE declaration is missing. After I added <!DOCTYPE html> to the stretched version, it solved the problem. Can anyone explain why?
When you save a page, you only get the version of HTML served from the server in its original form. Any mods to the DOM made after load using JS will not be part of the save.
EDIT
I could not trace out the exact reason for the error as the code is really cryptic! In any case, if all you want is to be able to reproduce the exact page offline, then you can do a ‘save page as..’ from your browser (choose web page, complete). I tried this with FF as well as Chrome and it is working fine in both cases. While opening the saved page, it might be best not to use IE as its a certified choker when it comes to even the slightest error in code. 🙂
The most likely reason for the error is an cross-domain AJAX security exception (fired when the calling client side script and called server side script are from different domains). The 2 variables namely, com_google_ads_apps_servers_cues_CuesRelease and com_google_ads_apps_targetingideas_client_TargetingIdeas seems to be initialized using the return of some AJAX call (which couldn’t execute bcoz of the secu excep), and as a result remain as undefined.