Safari 4 beta + Mail.app = strangeness?

Example strangeness
Example of the strangeness

Like a good little fanboy, I installed the Safari 4 beta on my aging iMac.  So far, I am really liking the new version.  Nothing earth shattering, but the performance gains are quite nice.  Even on this old G5, Safari seems a lot zippier.

I have noticed something really odd since installing the beta.  Mail.app stops rendering HTML emails correctly.  I’ll get the first few lines of an HTML email and then a bunch of whitespace.  If I resize the window, the email appears normally.

Anyone else seeing this?