I'm using a 7100i, but I'm guessing this may work for anyone else. And this will work only in SureType so if that's not what you want, this may be a useless post to you; however: As a matter of style, I *hate* to have the first words in my text messages and emails from being capitalized so I tried and tried to find a way. And this is how I do it: Type my word, if it auto-suggests (like it usually does), I backspace (delete) to the end of that capitalized word until the SureType list of other words appears. I say backspace "until" because on the first backspace to the last letter, nothing sometimes happens; and in that case, a second press of the delete, will generate the list.
In any case, once that list appears, two versions of the word I am using appears one in lowercase and the other with capitalization. I then either manually select the word in lowercase, or most cases SureType will automatically assume I want the lowercase word and leave it there.
I can't say if this would work in your password/search field issue, but it certainly has worked in my nonsensical desire to have the first words in my emails and text messages to be lowercase.
Hope this helps.