default html tags in container sometimes

I have noticed this on and off and not sure what triggers it.
sometimes, the htmlarea container has default tags in there as such as html, head and body open and close tags.

It mucks up page formatting is some cases. or even gives you the
"Terminated request because of suspicious input data." error.

Also, after I decided to disable htmlarea.... several system textarea fields would have this residual formatting still in place inside the text only textareas.

i tried deleting cache table and refreshing cache, but the oddity continued.

any ideas?

thanks.

sull