o.k.

I removed all the iCal and exchange setting from my iPhone and did all of the setup again (including the sync steps in Safari on my iPhone)

Now I have only one account (gmail as exchange) and no subscribed caledndar.

My calendar list now look like "photo.PNG".

but unfortunately i can see only my calendar - see "photo1.PNG" and "photo2.PNG"...

 

it used to work using the google's ical adress - but no longer.

i guess that the only option is using third party ical subscription.