ESQL/C 9.20 vs 7.23: changed CHAR vars behavior

We have migrated our INFORMIX 7.23 engine towards a 7.30.UC7 version. The ESQL/C used is now the 9.20.UC3 one. With the 7.23 engine and ESQL/C compiler, a program was able to store a null-terminated string value " " (one space) into a CHAR database field, and retrieve exactly this value into a C variable "Field" declared as "char Field[n+1]". Now that the database has been migrated, and after recompiling all ESQL/C sources, the same program acts differently: the C variable "Field" now contains '\\0' on the two first places, and spaces after (padding on the whole length). Anybody has an explanation of this? Is there a compilation flag or an environment variable, to achieve the behavior of the old version? Thanks a lot for your tips! Philippe JOB Siemens Business Services (BELGIUM)