General :: Battery Drain By Mobile Network Signal / Cell Radio?

I've ported a Hero ROM to a HTC Magic.Here's my problem:

Problem: There's a great battery drain when you're connected to the network (no data but just mobile network for calls/SMS)

Ported ROM: Sandwich Deluxe 4.0 .

Original ROM: Hero ROM

Kernel: carz-2.6.34.4 (fast and stable)

The mobile network drains battery.I'm not in a low signal-area. Everybody who uses the ROM has a drain.I'm using a 2.x.x instead of a 3.0 kernel for an ICS ROM, can it be that this mismatch creates the drain?The phone displays a singal strength of 0dBm 97 asu. (Not normal?)

What doesn't cause the problem? In airplane mode there is no drain at all. So it is unlikely that some apps causes the drain.Wifi, GPS, sync, ... are all disabled.

What do you expect from xdamembers?

- Confirmation if the kernel is the issue of the drain. If not, I would like to know which files (in ROM) are responsible for network signal.