Chantix and Insomnia

My husband and i have been on Chantix since the 4th of July - our Independence day - and took the starter pack for a week - on the 11th we quit smoking - it's going great with the exception that we are both waking up in the middle of the night - always about 3am or so - and can not get back to sleep for a long time - has anyone out there experienced this? We are starting to feel exhausted and of course a little crabby cause of lack of sleep -