Leo_vid..._kexts are a 10.5 version and they are not compatible with the new opengl frameworks (10.5.2 graphics update) and they are causing all of your graphics problems (balck....). You can try this, download this, extract and move the "patches" folder to the root do the graphics update again, boot with -s and type

mount -uw /
cd /patches
./replace.sh
./patcher cpuid.txt
./patcher cpuid-graphics.txt
reboot

edit the info.plist for your kext, nvdaresman, nvda40hal, geforce, and add only your device id, delete the others, copy into the extensions folder nvinjectgo open a terminal and type

sudo -s
(password)

cd /system/library/extensions

chmod -R 755 * && chown -R root:wheel *
cd ..
rm extensions.mkext
kextcache -a i386 -e
reboot

boot with -f -v