in recovery, go to mounts and storage
format system, boot, cache, and data.
then press the back button
go to install zip from sdcard
and flash the rom again.
sometimes it doesn't take right the first time (or in bad cases the first 9 times)
make sure not to try to change your recovery while your rom is messed up.
if the recovery borks too, while your rom is not booting, it'd be really hard to fix an Optimus V.