This page cites all the bugs that the author is aware of in all the Gepasi 3.xx versions.
Most recent bug is on top.
Gepasi crashes if an optimisation or fit are attempted without adjustable parameters. The predefined Ping Pong Bi Bi kinetic function is not being properly calculated. These cause the program to crash when running. If any volume of a compartment was not unity, the differential equations were not built correctly. An error in the file saving routine caused loss of precision on numbers smaller than 1e-16.