Japanese symbols don't display correctly. On some websites, I only see a long row of squares instead of what's supposed to display. The websites display correctly on both Chrome and Internet Explorer.
My system locale is in Japanese, and I'm using Windows Vista. The only program that has problems with displaying Japanese is Firefox 26. I used Firefox 2.0 before updating to this, and everything worked fine on FF2.0.
EDIT: Ended up being a user error, seems like I had some font conflicts.