"Brain Zaps" from Effexor XR?

I have been on Effexor XR since early July 07. I have had no problems until recently. A month ago my doctor increased my dosage to 225mg/day. For the last week I have been experiencing what I can only describe as "zaps" to my brain. They are increasing in frequency and I am starting to feel like I am in a haze all the time. Has anyone else had this problem, and if so, how did you deal with it?