I had this problem too, but fixed it with a simple code change in the email template.. if you look at email_template_welcome.html within the style tag theirs no comment tag to hide the style code from getting displayed!

code in red add to the top
Code:
<style type="text/css">
<!--
add to the closing tag..
Code:
-->
</style>
And if I used the re-send function, the customer would receive a raw HTML(or perhaps PHP too) code message starting like
not sure on this one, If it didn't work the first time, I normally go with a different email program for the second email.