I think I solve the mystery by removing most of the wrapping foam. I only keep a piece between the module box and the firewall. The engine starts in 1 flip, regardless of it being cold or warm. Looks like the wrapping foam prevents the heat to dissipate from the module.

Updated 5/13/2006: had 5 trips to the field since the "reinstallation". The hard to start problem never occurred since!

--qc