Help! Since the release of Firefox 18, I've been experiencing extreme difficulties with my e-mail provider's webmail interface. Background elements and content (navigation and e-mails) disappear, and in their place is just empty, blank white space. I can typically get these elements to reappear by resizing the browser window; however, the effect of this fix is often temporary and the elements disappear again, as if being spontaneously redrawn. Here's what I've observed: This problem occurs only at zoom levels other than 100%. In fact, the steps immediately below and above 100% zoom (90% and 110%, respectively) trigger the problem consistently. In addition, the webmail interface uses frames: one for the mailbox folder menu, and another for the main content area. This problem occurs primarily in the main content area when opening messages or composing messages, at which point the frame is redrawn to display the new content. I don't know if this fact is relevant or not. Avoiding zoom, or using the 'Zoom Text Only' option, can prevent this issue, but it's not an optimal user experience or long-term solution. I have tried booting up in Safe Mode, but the problem persisted. I have also checked Firefox Beta, Aurora, and Nightly versions, and all of them demonstrate the same issue. This issue did not exist in earlier versions of Firefox. I am using Firefox 18 on Mac OS 10.6.8.