When I search for a certain keyword my site is not there and it should be. I do not have this problem with any of the other hundred keywords I monitor. The keyword is my "prize" term and gets the most queries.
The easy answer is turn off personalized search. Done. Still having the same problem.
Next, I search using a proxy and there the term is, where it should be.
Next, I search from a colleagues computer and there the keyword is, where it should be.
This has nothing to do with keywords falling in and out of the index. When I use a well known site to check various datacenters the keyword is there, in all datacenters.
Could this be a Google glitch with personalized search?