Others too, but Yahoo is the biggest problem right now, cant send or get email with this going on....
If you just want to be able to use Yahoo email, here is an idea:
http://www.mozilla.com/en-US/thunderbird/and add Yahoo support:
http://webmail.mozdev.org/This doesn't fix whatever has caused your current problem with some websites not allowing you to type text in a readable font.
But it should get you access to your email.
It is a round-about way of solving your problem - but it may have other advantages for you. First, you just may like it better.
I do. So do many others.
You may have other email accounts that you can access with this free software too. Makes it fast, quick, and easy to check email.
In other words, I don't have to go to sites like yahoo.com, hotmail.com, gmail.com, etc., to check email anymore.
I rarely use yahoo email, but I check it occasionally. And I have no idea how long it has been since I last visited the website.
Just something to consider.....