One of the things I've always loved about CM was that importing HTML into Campaign Monitor did not re-write your HTML code. (Outside of tracking links and the like, of course.)
Let me say that I generally like the new import interface changes, but don't like that the box to write inline CSS is now checked by default. Since I already write my own inline CSS, I uncheck the box. (If I remember.)
I would expect that if I unchecked the inline CSS box, CM would leave my HTML alone, but when I viewed my test email source file, I see that some of my HTML had been altered. Some, but not all, of my <br> tags had been changed to <br /> tags. (My client insists that the emails be sent as HTML 4.0 Transitional.)
The <br> code change is not a huge deal, but I'd love to know more about how CM re-writes HTML and also request that the inline CSS checkbox be turned OFF by default.
Actually, we don't touch the code other than pulling the CSS inline when the box is checked, and of course converting the links. I just tested on my end with what I believe is your code that had a mix of <br /> and <br> tags in it. I converted all tags to <br>, imported it and viewed the source in the preview - and all <br> tags were left untouched. If you still feel this is happening, please contact support so we can look at your specific code.
My code does not have any <br /> tags (really.) If it matters, I was using the import from the web upload. I will contact support.
I'm having a problem with importing too. My email is getting space added between two images which is destroying the layout. I don't know why CM is adding space when Safari, IE7, IE6, and Outlook 07 aren't...
Most likely it is the email client adding the space, but in certain cases Campaign Monitor will break long lines of HTML to avoid other problems. So you might try breaking your longer lines yourself to avoid us having to add them.