Ive noticed that happen on a few occasions. Most of the time the font changes to some large version of Times New Roman, then I refresh or after browsing through a few pages it returns to normal. I guess some server might be restarting or something and it reverts to standard settings? I dont know, youd have to ask a techie at ezBoard.
Once I had the font change to some miniature version, it was like 10 font, and stayed like that for 2 weeks or so, and then returned to normal after I uninstalled a program (though the program was installed before the font changed).