ZD3000 seamless roaming doesnt work

[Skynet]

ZD3000 (25 AP license) and 5 7363 AP's - seamless raoming doesnt work, clients gets disconnected while moving from one to another.

[Skynet]

[Skynet]

1st ap - 7962

2nd AP - r300

When client moving from one ap to another client doesnt disconnect from the weak signal of the first ap and consequently doesnt connect to a much stronger signal of teh second ap.

[Skynet]

[Skynet]

2. Do we need a similiar versions of firmware on all APs?