Jeanne,
We've had a machine about 3 years now and have not had it happen even once.
We change the converter vial weekly, to be sure it stays clean -- so we're
certainly manipulating the assembly fairly often. So, I'm afraid I can't
offer any insight as to what is happening to yours.
Rod
NIH
Bldg 3, Room 106 MSC 0320
Bethesda, MD 20892-0320
email: rlevine@nih.gov
voice: 1 (301) 496-2310
fax: 1 (301) 496-0599