Kaspersky simply has more manpower and even Kaspersky sometimes add Malware only if a new Comulative update is released. Not often, but it happens.
BTW: Their respond is not very informative, just Malware(the name of) or not or if an outbreak took place they make an autorespond with an automatic scan-robot. But thats enough for me, maybe Avast could do that too!?
The respond of CA Etrust is intresting, if sending Malware via their Webpage.