Google changed results and a lot of sites dissapeared

for the last 2 years this sites have been on top on google..not anymore

[cr3ative]

Over night the sites offering accommodation in bucharest just dissapeared from the front page.
sites offering accommodation in bucharest
were on the first page with search strings like
bucharest apartments, accommodation bucharest,
and now all that is related to bucharest is gone.

Some of them still appear with strings related
to romania like: accommodation in romania,
apartments romania.

I do not understand why for bucharest they were removed since i believe that this are the most signifiant sites related to those query strings.

It is possible that google wants those sites to fight for the AddWords section? I will really appreciate any advice (i am webmaster for one of those sites :)
Some of them have some hidden keywords as i saw but if they were blacklisted it should been totally not only for the bucharest related queries. This is not the reason since some other sites have the same hidden keywords and they appear on the first page with bucharest apartments. (the only difference is that the keywords are framed).

Best regards

[edited by: cr3ative at 6:51 am (utc) on Jan. 28, 2004]

[cr3ative]

We first noticed this change on 24-25 January 2004. I dont believe is an alg change because all the other search strings show the same results as in the past.
Only the strings containing bucharest keyword show new results.