I've been plagued with a bit of a problem. I have a client site up (not my site), and Yahoo and Altavista (which I believe, are the same) sometimes "revert" to an old cache of my page, back in Dec. 24/2004. Everytime it happens I fall out of top 10 into obscurity because of poor coding for keywords, during that publish. Ironically today, I thought hmmm, maybe I'll try putting the "no cache" meta tag in my head portion of my home page. Completely surprising 10 minutes later I was back in the Top 10. Coincidence? Relevence? What sacrifices would I be making by having this meta tag in there? I'll leave it for now, but it was almost too quick to have been the cause?! thanks for any input!
I belive the nocache tag is an instruction for browsers, not search engines: GoogleGuy has indicated or at least implied that it has no effect on rankings: see http://www.webmasterworld.com/forum3/20742.htm