CLICK HERE TO READ WHAT WEBMASTER WORLD'S GOOGLE FAQS HAVE TO SAY ABOUT YOUR QUESTIONS REGARDING CAPITALIZATION [webmasterworld.com] AND UPDATES [webmasterworld.com].:)
It is pretty clear from trying out some searches on Google that Google makes no distinction between search queries conducted with different forms of capitalization. For example “KEYWORD” and “keyword” give identical SERPs.
However, this doesn’t necessarily mean that they rank a web page the same regardless whether it contains “keyword”, “Keyword” or “KEYWORD”. Maybe they think “KEYWORD” is spammy. I read somewhere here on Webmaster World that Google doesn’t like all caps in titles because it makes their SERPs look like one big promotion.
I guess the thought is that ALL CAPS will attract people to click on your title in the SERPs. However, I prefer to keep my capitalizations natural . . . Unless I am trying to make fun of all capitals.:)
Yeah it matters, all caps look silly, detract from the other content on the page, (from the user standpoint) and certainly won't help your position. Use of proper grammatical rules, spelling and punctuation will however help your users.