Michael,
For months I've been annoyed by a number of small breakages in Inkscape behavior. Knots and handles remained highlighted after I release mouse; rubberband rectangle stayed on if I accidentally ended it on a node; some other small weirdnesses. Nothing fatal, but rather annoying, and a sign of something broken somewhere.
Today I finally had time to do timed checkouts to find out when this thing started. What I found was your change back in August:
http://svn.sourceforge.net/viewcvs.py/inkscape/inkscape/trunk/src/display/sp...
I understand your reason for this change, but as you see, by enabling your own tool, you disrupted the work of most other tools that relied on the old behavior. So I would really appreciate if you rethink this change and implement it in some other less disruptive way. For example, you can add a flag to canvas items that would make them receive events while mouse is down, and use that for your connector tool handles, while all other canvas items would by default not receive events as before. Or you can add a flag to canvas itself to switch it to "pick while mouse down" mode only when in connector tool. Or you can come up with something entirely different. In any case, this situation needs to be fixed somehow.
-- bulia byak Inkscape. Draw Freely. http://www.inkscape.org