For some reason, CSS has all of a sudden become case sensitive in IE9. I have tried this on other peoples computers and the site displays fine in IE9, but on my machine it wont display CSS unless the case is right.
I can change IEs settings this to quirks mode and it will work, but it doesn't explain the strange behavior.
I have tried resetting all IE's settings back to default, clearing cache, but was not able to reinstall it.
Are you in standards mode? Historically IE has been case-insensitive for the class and ID selectors, but I understand IE9 is case-sensitive when in standards mode.
CSS properties and most values are case-insensitive, exceptions being url() where the webserver serving up images might have case-sensitive filenames.
CSS selectors are case-insensitive except for parts outside of CSS, such as #id and .class selectors. For more information see this question: Are CSS selectors case-sensitive?
