5D Mark II prone to dust on focusing screen

I've only had my 5D Mark II for about a month, and I've noticed it's very prone to getting dust on the focusing screen. It's not a big deal because the stuff knocks off easily with a single squeeze of a Rocket Blower.

But is this fairly typical of the 5DMKII? I've never noticed this issue with the XTi/40D/7D (cameras I've owned).

You know, the inside of a dslr don't vary that much, i don't see anyway a particular camera can be more funerable for dust than any other.

Same with a 7D, except you can't remove that focusing screen...

I just ignore it :P