Search result bug

Hi all,
It seems there's some strange behaviour in the "search filters" in both FF2 and FF3, at least in some computers...
Attached is an image with four screenshots of the searches and search results I got.

I was looking for the filter named Bronzerizer, but didn't remember the whole name.
You can see that in (A) I input the word bron, and get no results.
In (B) I input another letter, and the search word bronz gives me six results. Note that bronzerizer is not among them.
In ©, after adding another letter, I get the search results for bronze. Still six results, same results as before. Still no bronzerizer.
Only in (D), when the search word is bronzer I get only one result, bronzerizer.

The problem is, both in the name of the filter and in the keywords appears the word bronze, from search ©. The word bronz appears in the name of the filter.
Why didn't FF find the filter I was looking for?
Note that the online library search DID get the result for search ©, as do some other computers...
What would cause this?

Thanks...
As I said, it seems to happen only on some computeres, not all.