Some questions about testing

Hi, i present myself. My name is Mario and i'm subscribing this list by first time.
Why ? I just have a few questions in order to understand how testing works.
I use testing and i like it, but there some things i don't understand
Here I go:

Lenny is frozen. In short time it would be stable, right ?
What i expect from a frozen release is to be practically the same as the final release.
So why can i see some notorious bugs ?

* sound do not worked on two PCs where i've installed lenny
* can't quit from aptitude after a package install
* abiword do not show legible characters after a fresh install
* synaptic don't remember the 'Consider recommended packages as dependencies' setting
* gtk's file chooser dialog shows ugly widget arrangement

I mean, if lenny is close to be the 'official' release, when those bugs (and maybe others) will be fixed ?
I know those are not serious bugs, but aren't they bugs to be fixed ?
Is lenny ready ?

Regards & Thanks