gn_wendy - 6:42 am on Aug 3, 2010 (gmt 0)
What exactly do you mean by "broken"?
Definition of broken: the site:- operator returns bogus numbers for "About 1,240,000 results (0.23 seconds)", i.e. it will not return the number of a site's pages in the index (supl. or otherwise).
Using the operator to limit a search query to a domain, sub-domain and/or specific domain directory works superbly. That is to say, if you are using it to find information (as in: show me the page about blue sparkly fluffy widgets on www.example.com), you're golden!
About the broken pages-in-index - for "example.com" i got these numbers:
About 1,240,000 results (0.23 seconds) - example.com
About 12,900,000 results (0.20 seconds) - example.com -spellingmistake
About 9,400,000 results (0.38 seconds) - example.com -agkh
The actual number of indexed pages for "example.com" is between 3,500,000 and 4,000,000 (verified through other tools and painstakingly extensive research). The total indexable pages on "example.com" sum up to roughly 6,000,000.
An interesting note is that "example.com -spellingmistake" returns pages (URL only, no snipet, no title) blocked by the robots.txt.
This is nothing new - but it does really mess up the numbers, because Google will return the blocked URLs (and how many of them there are) when you use the site:- operator; further obfuscating the results.