I am running 7.x-1.21 and am seeing weird redering of the recaptcha module in IE8. Firefox and Chrome do not have this issue. Issue also does not appear in IE8 Compatibility View.

Example: http://hiram4.org/user/register

I changed theme temporarily to Garland and recaptcha shows fine. I have no idea where to being as I have not customized except for adding a few modules.