I have seen this happen several times, and it always seems to be a
problem with the oil-- suddenly the oil goes "bad". Try buying new
oil, or trying out the same type from another lab. I don't have any
idea of the cause of this problem, but give changing you injection
oil a try.
William G. Kelly, Ph.D.
Assistant Professor of Biology
1510 Clifton Rd
Atlanta, GA 30322
phone: office 404-727-6461
e-mail: bkelly at biology.emory.edu
"If people concentrated on the really important things in life, there
would be a shortage of fishing poles"-- anon.