I'm glad I finally found a place where there might be some answers from other disgrunteled yahoo customers. Sadly it looks like there is little chance that yahoo support will respond. Yes, I've tried Yahoo help to no avail.

I'm having the same exact problems as described by dgarvey. I update my Norton AntiVirus regularly. My probelms started earlier in November. Won't let me send, or copy (from a doc) into the reply field. I also noticed more spam getting through in my yahoo account.

I won't hold my breath for help from yahoo, but I will attempt all the fixes described here. Thanks for the help, yahoo users.