N3 very often crashes by itself

when i setup score more than 14 instruments od Miroslav Ph. Simple when i add 15. instrument it crashes,
when i add altiverb for first time its ok, but when i want to access altiverb trough mixer again it crashes,
and i opened help, read something, when i closed help N3 crashed.
I have good computer with 4gb of RAM, E3300 but no sound card yet.
Also i have problems with dynamics.

There is no crescendo playback in this situation. The first 3 measures are playedback in pp constantly, while in 4. measure dynamic changes to f suddenly.
Trills are not playbacked with Miroslav Ph.
So, please help.