Gentoo hangs in boot.. (dm-multipath, custom format hand ??)

[te36]

Installed latest gentoo according to handbook last month, and it booted "fine", but yesterday it must have stopped, and now when rebooting, it hangs after trying to insmod "dm-multipath.ko". I commented that out, now it gets past next point "setting system clock using the hardware clock [UTC]", but then last message is "loading custom binary format handlers".
Q1: what should i do ?

Q2: hardware is running a 32 bit version of gentoo for > 10 years now, but procastinated to update, so this is a new install on a separate root partition. The 32 bit gentoo still boots and runs fine, grub boot partition code is also still from 32 bit install.

I actually can not get the 32 bit grub installation to load the 64 bit kernel ramdisk. Is that a bug or a feature ? Thats why the 64 bit kernel must be trying to load kernel modules from /lib. But i am a bit worried of killing the working grub install, so that i wouldn't even be able to boot back into the 32 bit gentoo to help me recover/fix the 64bit install...