Budeprion and intense headaches

I have been taking the same dosage of budeprion for about 18months. About a month ago, I decided to give it a go and attempt to start the weaning process by reducing my dosage just a bit. Within a few days, my mood was nasty and I was having intense headaches. I switched back to the same dosage I had been on prior to that and thankfully the headaches subsided. That was about 3 weeks ago.

Here's the problem: I have still been experiencing the same headaches only not as intense. I am positive it is the meds because I'm fine up until I take it and I've tested this several times. Between my doc and the pharmacist, we haven't been able to figure out the culprit. The manufacturer and all the specifics about batches of pills are the same. At this point, I am going to try another manufacturer because my doc has no idea what else to do. Anyone else experience this?