I've been wanting to run an x86 binary on my Sprint Epic 4G under Android (sorry, I didn't get the N900, although I really considered it). Anyways, I was running into the same fork problems you guys were having. I asked in the qemu IRC support channel and was referred to this bug:

https://bugs.launchpad.net/qemu/+bug/739785

The relevant comments for a fix are #32 and #34.

I put the patch in a file called nptl-patch, and I extracted qemu and went to the qemu-0.14.1 directory.

# First, I needed more ram to compile translate.c, so I created and mounted a 384MB swap file on my sd card (I'm sure all your paths and such are different, but you can translate):
dd if=/dev/zero of=/sdcard/swap.img count=786432
mkswap /sdcard/swap.img
swapon /sdcard/swap.img
# don't forget to swapoff later when you're done with it!

# apply the patch
patch -p1 < nptl-patch

# configure and build
# note: I had to install a few packages in order to be able to run configure, but I forget what they were now, they were obvious based on the errors tho
./configure --static --target-list=i386-linux-user
make
make install

# I had a debian debootstrap --foreign install in /i386:
cp /usr/local/bin/qemu-i386 /i386/usr/bin
chroot /i386

And "ls" worked I proceeded to /deboostrap/debootstrap --second-stage, etc.

I don't know if this is useful or not for wine, but I wanted to share it regardless as another potential avenue for you guys. Good luck!