[E986] No network signal, no IMEI

Hi,

I flashed now 2 different roms from this forum, going to stock before with LGMLauncher and it's always the same:
After a couple of days I lose my IMEI and no signal from network.
Also, when I try to flash modem/baseband i receive the error "Failed to mmap aboot. Error loki-fying the boot image"
I use CWM for recovery.

Thanks.