How can one prevent tabs from getting cleared?

Hello,

Upon clearing the history in Safari, my open tabs get cleared as well. How can I prevent this bug from persisting?

Note: The history was cleared by using the [History] > [Clear History] path.

Specifically:

If I clear my history, then the next time I open Safari, all the tabs that were open are now blank and defaulting to the "Top Sites" page.

If I use the [History] > [Reopen All Windows from Last Session] path, all the tabs show the title of the web page they once displayed, but for a split second, and then immediately default to the blank "Top Sites" page. The time the tabs display the title of the web page they were displaying before the history clearing is so short that I need to "Reopen All Windows from Last session" multiple times just to deduce what one tab title is saying. I'm eventually able to figure out all the tab titles, which allows me to retrieve *most* of the lost paths of research down which I was traveling.

If anyone knows whats going on and/or how to correct this issue, please help. Thank you!

Relevant System Specs:

-Mac OS X, version 10.7.5

-Safari , version 6.0.1 (7536.26.14)