[CM7.2 RC4] Data Connection turning on but can't connect to the internet

I had this problem... i really like the CM7.2 Stock and Based-Roms but i always had this problem...

My firmware is DXMJ1

I flash stock rom using odin

boot into recovery

installed cm7.2 specific kernel

cleared data/cache (wiped)

flashed the ROM zip

Then it boots normally....

I put the EXACT details for the APN of my network
even the name

data turns on but can't connect

tried wipping again and flashing

i done the APN thing again but nothing works