Stuck in old version of Yahoo mail

With the recent news about Javascript security flaws in Firefox, I
turned off Javascript, then logged into my Yahoo mail account. A
message popped up saying that I needed to enable Java or switch to the
old version. I switched to the old version, thinking I could switch
back later easily.

I was wrong. I can't for the life of me figure out how to get back to
the Javascript enabled version. Even after switching Javascript back
on, or trying other browsers (eg Internet Explorer, which had never
had Yahoo mail problems, and I never disabled Javascript on IE), no
luck.

I even called Yahoo's free phone support, and they had me clear out
all the "objects" in the temporary internet files folder, and
re-install java, to no avail.

Anyone experience this problem and come across a solution? The old
version of Yahoo mail is tough to live with.