did it work with this ROM/setup before and stop working or has it never worked?
If it never worked, go to the thread for the ROM you have and ask for help there or choose another ROM.
Few things I would do if it worked before and just stopped:
reboot to recovery and wipe cache/dalvik cache
fix permissions
from settings menu update prl/profile
reboot
If that doesn't fix it, I would call boost and make sure your area isn't experiencing outages..
Lastly, if it's not boost and the above non-invasive fixes don't work, I would do a backup and wipe everything including your sd card and do a fresh full install of the ROM, then check to make sure the issue is resolved, if not then you have an outage going on or the ROM itself is to blame... generally you should post issues on the thread of the ROM you are using.