As you know, I have at home a dual opteron system. This machine is recently upgraded up to 4GB of RAM… so I decided to install a new Linux kernel (at that time it was the 2.6.22.5).
After the upgrade, the nspluginwrapper didn’t work any more! 
A received an error like:
npviewer.bin: cannot execute binary file
But Google didn’t gave me any solution… but after some brainstorming I realised that I didn’t enable the IA32 support in the kernel.
It is about the next options in the config file:
CONFIG_IA32_EMULATION=y
CONFIG_IA32_AOUT=y
Update: I submitted a bug at bugzilla of Gentoo and there is a discussion about it 
