I have the same problem with IE8 plus Windows 7. Today I received the notification about the update and after installing the update in some website the red (or grey) icon is not visible in the toolbar (and right mouse click on page => lastpass => doesn't show options) and on other site it is visible (including right mouse click menu).
I already removed the latest version, downloaded it from the website and installed it again and rebooted. Didn't help...
I have multiple tabs open and on the following sites I see the icon (and right click menu):https://www.clickbank.com/login.htmhttps://7search.com/scripts/advertiser/v3/login.aspx
While on the sites below the icon is not visible during the same browsersession:https://adcenter.microsoft.com/?mkt=en-ushttp://lastpass.com/index.php
When I go to "my lastpass safe" via the red icon I see the message "Please Enable Your LastPass Internet Explorer Browser Plugin" with instruction on how to enable it. However, it is alread enabled.