Having had the same problem recently. Although, mine was mainly caused by the com port being reassigned somewhere along the way.
To help with the arduino program differences.
023 has some older routines and calls.
1.1 runs I think newsoftseriel (or I have this the other way around) as a driver off the top of my head and a few others, that can get in the way of handling certain calls within the program.
perhaps search around for the updated version of your program which calls the new routines.