XPages Extension Library
After close (OK Button) the picker and try to load the picker (there are some values in the field) you get a JS error: "Object doesn't support this property or method." at line 16 char 21956.
Some fixes in this area went into the latest build. Is it what you're using?
Last versione (10/17/2010)
Thanks for reporting the issue - It is fixed on SVN and will be in the next build