Kaspersky security products work at the operating system level and Firefox does not interfere with that protection.

What happens is that Kaspersky's browser add-ons that load into Firefox are checked for compatibility, and if those add-ons do not indicate compatibility with Firefox then you are notified that they will be disabled.

Kaspersky has posted a page describing the incompatibility. You can review that and then decide whether you can live without the add-ons (get Firefox 4), or you really need them (stick with Firefox 3.6).

Kaspersky Lab products and Mozilla Firefox 4.0: co-working peculiarities

It is the responsibility of a browser to be compatible with anti-virus software and not require the user to disable it until the issue is addressed. Firefox had no right to release 4.0.x with such a glaring hole. For a browser to turn off and leave off anti-virus software because of the browser's shortcomings in inexcusable.

I do not have this issue with Chrome or Safari so obviously it can be done, Firefox just chose not to. When Firefox 4.0.x went to install it simply said it would disable Kaspersky and it would have to remain disabled until Firefox fixed the incompatibility. Virus and mal-ware writers are probably very pleased with such a decision but I am not. While Firefox is a nice browser it pales compared to the need for good anti-virus/mal-ware protection.

Notify me again when you have solved this gaping hole. Maybe then I will upgrade, if I am still using Firefox at that point.

1. Your anti-virus software will NOT be be disabled, just the Add-ons that Kaspersky installs in the browser.
2. It is the responsibility of developers of Add-ons to make sure that their Add-ons are compatible with any/all browsers (the products mentioned in the link that jscher2000 included are Add-ons to Firefox).
3. You need to read the following part in the link provided by jscher2000 more closely, as it says Kaspersky Anti-Banner and Kaspersky URL Advisor are the problem:
   • "...incompatibility of Kaspersky Lab products with Mozilla Firefox 4.0..."

Good day,

I totally understand what is being said here, but the problem still remain. My question to you is; when the next version of Firefox is design, will it take in consideration Kaspersky Add-ons incompatibility issues?

Putting aside who's responsibility it is to make software compatible, I believe you can understand that I won't dump my Kaspersky Anti-virus (which I "bought"), to find a new Anti-virus which has Add-ons that are compatible with the new Firefox. It is hard enough for us, the "not so" computer friendly to begin with, to start figuring these things out.

I might add, that when I got Kaspersky originally, their Add-ons WERE compatible with Firefox..... It was not Kaspersky who upgraded their Add-ons, but Firefox who upgraded its software.

Take note that I will be sending a similar email to Kaspersky, as well.

I thank you for taking my concerns into consideration and will wait for an answer. Thank you.

Add-ons need to be compatible with Firefox, not the other way around!

Have you checked with Kaspersky about the status of those add-ons now? This thread was started 5 months ago, and a lot may have changed in that time.

Kaspersky chose to provide those unnecessary add-ons (Firefox works fine without 'em) and it is up to them to keep them updated as Mozilla releases new versions of Firefox. If Kaspersky is unable to do that, they really oughta tell their paying customer's that they aren't capable of doing so, and stop "advertising" those add-ons as "features" of their program.

Kaspersky has been issuing patches for new Firefox releases very promptly.

For Firefox 7, they issued a patch on October 6th, less than 2 weeks after it was released. http://support.kaspersky.com/kis2012/tech?qid=208285490

But of course they can't guarantee the timing, as patches obviously need careful testing.