GUI problem setting breakpoints

Well, I'm picking up JSwat again after a long time, in a situation where I
can run it properly in GUI mode -- something I couldn't do when I last
played with it -- and right away I noticed some weird behavior.  Whenever
I right-click on a line in the source file and set a breakpoint, it reads
the click as hitting a line 10 or 20 lines below the one I actually
clicked on, even if it's not currently visible.  It gives me a lot of "no
code at that location" errors, and of course when I do succeed in setting
a breakpoint it's in the wrong place.  Is this a known problem?  I
searched my mailing list archive and bugzilla without finding any mention
of it.  Maybe it's just me.

Someone suggested that my class/jar files might be out of sync with the
source files, and that might account for the misplacement.  I don't think
they are, but if there were, could that possibly cause the problem?  (I
would have thought not.)

I'm running JSwat 1.7 (also reproduced in 1.6) on Mac OS X
10.2.something.  Oh how I wish Apple would get their JDK 1.4
implementation out the door.

Regards,
Matthias