That is really strange. I get wierd stuff like that happening but it is usually that my browser has not completely loaded the CSS file for that website for some reason.
If it happens to me, the first thing I do is clear my browser memory. Then refresh/reload the screen. It usually cleans it up for me. I have not had it happen on CC's website forums. But has on others.
If you are really curious, you could research it:
If you are in Chrome, and it is still happening, highlight part of the words that the font has gone strange. Then right click and select "inspect Elements".
This will take you to a screen showing the elements and code. In the right hand box you will see under "Styles" what and where the font style is from. Note you will want to make sure that you have "Show inherited" check box clicked so you can all styles effecting that area of the webpage.
I use this often, when I find things not quite right in my own code. Then I find out that I should of added an element to the div class tag to get what I wanted. Since the class I was using did not have the element, it just pulled an inherited element from before. It's a great tool.
In the left hand box you see the code with arrow bullets. You can expand out the code by clicking those to get deeper... if you wanted.