Hey Guys, I found a great program that will fix the font sizing issues found in EPUB files, when you copy them to your KOBO E-Reader!!
Simply download this program thats attached to this post.
Once you do that do the following
Download the Zip file from this post
Unzip the Program using WINZIP (you can google for it and download it)
Unzip the directory to your desktop
Take all of your E-Books that you have downloaded and create a directory for them on your desktop, such as E-Books
Run the Program you downloaded here
it will ask you to select a directory
select your E-Books directory
it will then convert your EPUB files
Once this is done, it will allow your font size to be adjusted in the Kobo E-Reader
Copy the EPUB books you converted to your Kobo, just copy them to the root directory of the kobo
Open the books once the Kobo Updates new Content
and here's the fixer for os x.
Here is a Video Tutorial we have done, that documents the entire process.