Bluetooth Mate: Error: Resource busy (link added)

i got my BT-Mate just working fine, stopped it and BAM error occurs:

"avrdude: ser_open(): can't open device "/dev/tty.FireFly-9DDB-SPP-1": Resource busy"

if i stay on tryin sometimes it just works, then not. can't make out any system in the behaviour even though there must be one...

i found one dead end in the old forum, but no one answered it yet.

and this one: http://www.arduino.cc/cgi-bin/yabb2/YaBB.pl?num=1201091018

about the same problem with the Arduino BT. seems to be a Mac Os Problem, but I cant figure out where it comes from and how to fix it.

is this a known problem? is there a bugfix for that? or a work around? would be great...

what i forgot: Mac OS 10.5.8 MacBookPro; Arduino 0022