Flash 9 crash problems

[Novembre]

I have upgraded my 7.0-RELEASE system to RELENG_7 as of 02/19/2009. I had
Firefox
2.0.0.12 installed before the upgrade. Then, I installed Adobe Flash 9
following the
instructions here
http://docs.freebsd.org/cgi/getmsg.cgi?fetch=51075+0+archive/2008/freebsd-emulation/20081102.freebsd-emulation

So I have linux_enable="YES" in /etc/rc.conf, compat.linux.osrelease=2.6.16
in
/etc/sysctl.conf, and OVERRIDE_LINUX_BASE_PORT=f8 in /etc/make.conf, and the
following line in /etc/fstab:
linproc         /compat/linux/proc      linprocfs       rw      0       0

I then installed www/nspluginwrapper and www/linux-flashplugin9. The plugins
showed
up in Firefox when I type about:pugins as
----------
Shockwave Flash
File name: npwrapper.libflashplayer.so
Shockwave Flash 9.0 r152

MIME Type       Description     Suffixes        Enabled
application/x-shockwave-flash   Shockwave Flash         swf     Yes
application/futuresplash        FutureSplash Player     spl     Yes
----------

After that, I can see flash videos on youtube and other websites. The
problem is that when
I close the tabs containing a flash video (most of the times when it is
playing, but sometimes
even when it is paused), npviewer.bin crashes with a core dump
(npviewer.bin.core) in
my home directory and it leaves a lot of zombie npviewer.bin processes
running. Note that
Firefox does not crash and is stable. At this stage, if I want to view
another video, a gray
box appears and nothing plays. If I kill all the zombie processes, the
videos load and play
just fine.
Another minor problem is that if I view the videos in full screen mode, it
appears that some
frames are lost, and the video is not smooth.

This is the result of 'uname -a'
FreeBSD rsx4.physics.uiuc.edu 7.1-STABLE FreeBSD 7.1-STABLE #0: Thu Feb 19
18:46:55 CST 2009
soheil at rsx4.physics.uiuc.edu:/usr/obj/usr/src/sys/RSX4CUSTOM
i386

Does anybody know what I should do to fix this?

Thanks a lot :)