I just noticed that the reCaptcha is misaligned using IE8 and Label Placement: Left Aligned.
It appears that the {margin-left:32%} doesn't work with IE8, but does work in IE7 and FF. Nothing serious, maybe a bug fix in later release.
/* fix captcha alignment for IE8 ---------------------------------------------------------------------*/
.gform_wrapper .left_label #recaptcha_area #recaptcha_table, .gform_wrapper .right_label #recaptcha_area #recaptcha_table {margin-left:32%}