There are many ways propageted to update the BIOS of your Thinkpad, if you don’t have access to a native windows [ubuntuusers.de, thinkwiki.org, thinkwiki.org (X_Series)]. I tried some (via Grub or put the ISO image with dd on a flash drive — watch out to not destroy your drive!), but finally here is what works for me.
Note: in order to write grub4dos in the MBR of your flashdrive the right command is
not sdb1, for instance.
Hope this helps!
Updating your BIOS at your own risk.