Soaking the reed in vinegar usually doesn't do anything good for you, nor does it soften the reed.

Check the opening of the reed to be sure it is correct. If not you can manipulate the reed to get the opening correct. The only other thing I can suggest is scraping the reed. If you do not already scrape or fine tune your reeds you should get started doing it. If you take private lessons have your teacher help you with this one. If you don't take private lessons then I might recommend you find a quality college or university nearby and see if you can get an advanced student or graduate student to help you with your reed.

IRK! I think that the hardest part of the oboe is the reed...it's always either too hard..or too soft...(sigh) Well...for me, if the reed is too hard, I pinch it shut, then I blow more...that usually works..but then my band teacher says that I'm too loud, but perfect on the solos. Ugh! *crawls over to a corner*
Peace, Love, Oboe!
K.K

I would not suggest pinching the reed shut very much, as this will make the reed sharp and dampen the tone (and volume) significantly, as well as not permanently fix the reed. Try scraping off a tiny amount of cane, particularly near the heart of the reed with a flat, sharp knife. Even better, if you have a teacher, I would ask him or her to help you. Also, you could experiment with different amounts of time to soak your reed; perhaps you're over-soaking?

As factory-made reeds go, Jones reeds tend to be expensive and inconsistent in their quality (within my experience). For future reference, I would try companies like Emerald and Forrest, as these tend to be better quality.

I'm wondering why you switched from medium-soft to medium. Oboe is not like clarinet or saxophone, where one goes to harder reeds as one grows more experience. In oboe-playing, the most experienced players are able to better direct their air with their embouchure.

I also think that the reeds from Jones are expensive and the quality is low. If you play with european type of reeds, the one from http://www.britanniareeds.com/ are cheeper and better.