Hi! I have a Vbob I bought quite a few months back. About 350 rounds through her like you. I must say mine is perfect. I've hit quite a few bullseyes and other shots stay in a 3-4" radius. I like the Heinie 8 sights very much compared to Novaks. Others at the range shot well, too. I also have spinal injury/damage, but thank god its mostly lower back. I hope it's just the wrong front sight and they get you fixed up, which I'm sure they will!
Here's my report
http://www.cotep.org/forum/showthread.php?t=8686
I used this picture as a reference when I first started shooting with these sights, but I'm sure you know what you re doing!
Great gun and good luck!!