bison 1.875c is incompatible to 1.35

Hello, all. I have some version incompatible problem with bison application. Help, please. Details: My application (Verilog parser) was compiled on Linux about one year ago with code from bison 1.35 and worked correctly. Now I recompile it with the code from current installed bison 1.875c . biso

Parser generated on Bison 1.5 (and later) does not start a parsing

Hello, all. I hope some one already faced this problem in past. Who can help, please? My Verilog parser, generated by bison does not start a parse process. It happend in bison 1.50, 1.875c and latest 2.4.3 But it works fine, when generated with bison 1.35 !!! What has changed from 1.35 to 1.50?