Not meaning to sound like an arse, but this topic really should've been posted in the 'Mass Effect 2 Official Campaign' forum, this isn't really a 'PS3 technical' query despite what you think.
I am curious as to what 'update' you are referring to because that setup of yours would NEVER work, so either you've got mixed up somewhere in what you think is true or you managed to have some major glitch when you played on the 360 version when you used that formulate. With everyone recruited and making it to the final stage of the Suicide Mission, having 2 of the heavys not 'Holding the Line' is always a recipe for a death and with Mordin not being in that lineup, then yes Tali is next to die.
Basically put... pre-Kasumi your playthrough at the end looks like this.
Mordin, Garrus and Zaeed safe due to being final battle squadmates and escort respectively. Leaving you with just Grunt, Miranda, Jacob, Thane, Samara, Miranda, Jack and Tali on door defence duties
Now I'll link the main topic you probably could do with reading in a bit, but basically put, the above team holding the line has a defence score of 15 and you need 16 to get everyone out alive, thus Tali dies.
Now, with Kasumi added to the group... it's same as above but now you have a score of 16 and you need 18, thus Tali still dies because she is still numero uno out of those people to die and thankfully you don't have a lower score which would mean less deaths.
Basically put, as Shiratori mentioned, if you swap anyone of the door defence team with either Garrus or Zaeed and everyone will live.
For more information on this, please read the topic I've linked
here as it'll further explain what I am talking about above (Note anyone not wanting the Suicide Mission spoiled, really shouldn't be reading that topic

)