I was trying to edit the per queue email notification
address for 
new issue announcements. An empty value
means use the 
tracker specifed annoucment address. I
tried to set one of the 
queues to use the default email
address, but I was unable to set 
the property to empty.

It is caused by the "if value" test in the 
following code.

1.1 (richard  30-Aug-02):   # only add the 
property if it has a value
1.1 (richard  30-Aug-02):   if value:
1.1 
(richard  30-Aug-02):       # if it's a multilink, split it
1.1 (richard  30-Aug-
02):       if isinstance(cl.properties[name], 
hyperdb.Mult
ilink):
1.1 (richard  30-Aug-02):           value = 
value.split(':')
1.1 (richard  30-Aug-02):       d[name] = value

If I 
change that to "if 1" then I can blank the property.