What kind of problem is OS X saying it is having? if it is simply that the permissions are incorrect then you can boot up via "-s" and perform the following:

/sbin/mount -uw /
cd /System/Library/Extensions/
chmod -R 755 * && chown -R root:wheel *
cd ..
rm -R Extensions.mkext
kextcache -a i386 -e
reboot


this will simply repair the permissions and rekext your Extensions folder for the follow-on boot.

If the problem is not the permissions, let us know...

EDIT: glad you caught that.... "-x -s" should have been what I wrote so you would boot in safe single user mode instead of simply single user mode. Thanks.

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