Is there a way to make a custom vector brush smoothly meet at begging and ending of the stroke?

Is there a way to make a custom vector brush smoothly meet at begging and ending of the stroke, such as with a circle?  I'm trying to create smooth circles with a brush and Wacom.  I want a brush rather than a mathmatically perfect circle with a perfect stroke weight-thickness, but I don't like how the two beggining and ending join up.  i like the slight variations of human imperfections one gets when using a vector brush, but there must be a way to make the joing points look more smooth, rather than an after-thought prgramming fault, right?  Is it possible? 

The image below shows my attempts to make as smooth a joint as possible, but it still looks too much like it wasn't meant-to-be.

I'm using Ai CS4, Mac OS10.8.4

Thanks!