Why do shortcut keys become active when I'm replying to an email?

The last few days, when I try to reply to an email and start typing in text, the shortcut keys are active and I can't type the shortcut key letters. It doesn't happen all the time. Anyone else having this problem?
Why do shortcut keys become active when I'm replying to an email?
YES!!! I hope someone at yahoo can help us with this - it is very frustrating. I'm considering switching back to the classic e-mail if it doesn't get fixed soon. thanks for posting your question - you're not alone.
Reply:Ugh! I too have been having this problem with the shortcut keys on my reply messages and it's driving me NUTS!! Hope we get an answer soon!