We're experiencing problems with previewing our pages when in edit-mode. The content of the pages ends up way out to the right of the screen so to be able to see the content we have to scroll to the right. As far as I can see in the rendered HTML of EPiServer the reason for this problem is that some kind of IFrame that EPiServer uses to show the preview of the page gets, in our case, the width 14458px. The id of the iframe that gets this width is in our case "epi_local_AutoResizingIframe_0" so I'm a bit curious about what "AutoResizingIframe" in this case does? Has anyone else experienced this problem?
I haven't seen a behavior like you describe with the iframe. What more can you tell me about HTML and CSS of that page?
I believe I've managed to pinpoint what's causing the problem to occur. As our first element on the page we have a <header>-element and connected to this we have the following css:
This will result in a long line in the top of the page, in this case most certainly wider than what the screen is, don't ask me why it's done like this, I will have a talk with our frontend developers on monday :-)
However, it would be interesting to know why this css, that worked fine in EPiServer 6 doesn't work in EPiServer 7?
Instead of setting a fixed width you could use width: 100% or set right: 0; (without any width).
I've had the exact same problem, in my case it was a Facebook login button (created with FBML) that caused the exact same problem described above.
<fb:login-button autologoutlink="true" perms=""></fb:login-button>