It looks like you have enabled Internet Explorer Compatibility View.
Gmail works best if you turn this off.
Even though this is followed by two links, "find out how to do this" and "dismiss", I am of course getting numerous calls/email stating they can't do what it is asking of them from the instructions and this would be because you are not actually using the Internet Explorer but a web browser that emulates the Internet Explorer.
So what's the solution? Click on DISMISS and ignore it for starters, that's if you really want to use the Avant browser but what I suggest and have been suggesting for some time is to start using the Google Chrome browser as your main "default" browser and keeping the Avant browser as the backup for those occasions a website doesn't appear quite right within Chrome and/or the website states you must be using the Internet Explorer. Since the Avant Browser is 100% compatible to the Internet Explorer, you DO NOT need to use the Internet Explorer but simply use Avant and all should appear fine.
It is always good to have a backup browser installed on your system and since the Internet Explorer can be disabled within Windows 7 (I typically do this), you should have a browser that does emulate this IE browser.
If you aren't sure how to make Chrome the default browser, you can follow these simple instructions.