I am seeing a bitshift: problem using GZip. I can show you, it's east to 
test.

To replicate, load Crypto and SecureSession.58. In the 
SecureSessionServer>>#initializeOnVatTPIdentity: you can set compressed 
to true. Then run the connection and data tests. 
install3DesNoCompressionOn: is where it is used.

Thank you,
-- 
. .. .. ^,^ robert