cm10.2 update wont boot first time, cant access recovery mode again
So i wanted to update to cm10.2 (from 10.1) , i am using a i9000 and clockwork mod recovery.
I wiped the relevant caches, formated /system then flashed the file from my sd card. Everything seemed to work alright (no errors) , but now the phone wont boot on its first attempt (longest i have left it so far is about 20 mins).
The main issue here is that i cant boot into recovery from it being off. I have tried volume down and power (i believe this is the correct combo) , all i get is the samsung galaxy s splash screen over and over (flashing every 3-4 seconds).
So what is the best way to proceed from here? (in order to just go back to cm10.1 probably), shall i use odin or something to reflash cwm? or to flash cm?
EDIT : i do have a backup which i made with cwm before the flashing, and have extra copies and whatnot. So how would i go about getting cwm to work again?
Im not quite sure what to do at the moment, any advice would be handy.
Thanks in advance