The X-Plane plugins have been updated.
The current version is now 3.4b3.
Please see the first message of this thread for the download links.
http://www.inivis.com/forum/showthread.php?t=7032
Previous versions of the plugin could cause hangs and slowdowns when updating some objects. This one has been tested by a few people and it solved the problem for them. It was also reported that this version feels a bit faster - I'd be interested to know if others notice this.