Extension authors generally specify a range of compatible version numbers. Firefox often ignores this range and runs an older extension anyway, but where the extension specifies that strict compatibility is required, or if the extension contains compiled (binary) components, then the range will be honored and the extension may be disabled after an update. Many security vendor toolbars and extensions fall into this special category.

Some security vendors work on updating their browser extensions while Firefox is still in beta and release updates close to the time of Firefox's release. (Norton does this.) Other vendors wait until after the final release, often a few weeks, before releasing their updates. Kaspersky falls into the second group.

You can follow the status of Kaspersky's updates on its forums. One way to search is using Google to target the forums: https://www.google.com/search?q=site%3Aforum.kaspersky.com+....

Based on various posts, the next update (patch B) appears to be scheduled for September 15th. That may be for the 2014 suite. You're probably entitled to a free upgrade if you just got 2013.

But... don't too excited: Firefox 24 is scheduled to be released on or about September 17th.

Thank you so much "jscher2000". All doubts are now clear and really thanks for the quick reply...

Keep up the good work! :)