Yet that appears to be what they've done. Perhaps not per page, but per site. We are keyword1 keyword2, obviously those two words are used all over the site too and we were nowhere for phrases with those keywords either.
Then we complained, then we reappeared for those keywords. We think they simply added those words to an exception list because keyword2 is the group name of a set of other keywords, keyword2a keyword2b keyword2c.... Obviously those keywords are all over the site and we don't rank on anything with those words.
I can literally put a 15 word product description from our catalogue into Google and there are 3 results and we are not in that 3. Yet the same query in Yahoo brings up the best two pages from our site for that product as 1 & 2, with 4 other results that are simply scraper sites hanging off us (not 302s).
The only result set worse than Google is Teoma which does not appear to have any pages from our site at all. Kanoodle even correctly chooses 2 good pages on that term as 1&2.