This has nothing to do with CFW, it's an issue with CoD 4. Disconnect your ethernet cable from your ps3 and launch Cod 4, it should start without any problems. Then connect your ethernet cable back in and sign-in.
It's not a yes and no error Tho I've tried disabling connection, it shows the cod4 logo then exits to the XMB I thought it was the eboot being modified do you know anywhere that has original EBOOT.BIN for blus30072?