semi problem setting paragraph-start

Greetings, I've been getting strange errors in filladapt for quite
some time now and we think we've tracked down the problem to SEMI.

Here's the thread:

http://thread.gmane.org/gmane.emacs.devel/68275

The code is in semi.el (I'm using the latest version, in Carbon
Emacs): 

(defun turn-on-mime-edit ()
    ...
    (setq paragraph-start
	  (regexp-or mime-edit-single-part-tag-regexp
		     paragraph-start))

The problem is that paragraph-start is set here many times so it
becomes very very long. 307 nested groups. 

One of the commenters in that thread noted that "turn-on-mime-edit"
must have been called repeatedly. The folks on emacs.devel suggest
that it's necessary to "call make-local-variable on paragraph-start."

Does this seem like a problem? What else can I do to help track it
down?

JDO