Interesting (forgive me if someone mentioned this - I didn't read all posts). I have never, ever, never heard anyone pronounce it with the "a" sound. Only as "ology" as in psychology, sociology, etc. When I clicked on this I thought the question was going to be on the pronunciation of the first syllable, where I have heard discrepant choices. Most people I know pronounce it "jean" (long e), but a not insignificant number of people pronounce it "jen" (short e).
Nick
OK, now I feel silly since I see that this thread has been resurrected from the moribund and is over 6 years old! PLEASE, PLEASE, PLEASE add a date to original poster column so we can tell when this happens.