Problem with oracle ref cursor in VB6

This is Aditya ,we are working on a Project, in which r getting a peculiar problem .

The project is in Visual Basic with oracle Database and the ODBC was Intersolv ODBC driver for Oracle. The Project was developed 2-3 years back. Now we need to add new features to the existing system.The project is working fine with the Production Database. Now we created a Database for development as just replica of Production database.
We are encountering the following error while working with the new Development environment and application closes abnormally.
" 0x286a87cf" referenced memory at "0x00000047" the memory could not be read

While debugged we found that the problem is encountering only when some stored procedures which are using "REF" cursors are called from VB code.We recompiled all procedures in Development Environment.

The project is working fine for production (original) database but not working for development database (replication) and also working when calling to procedures, which are not using ref cursors in Development Environment. When we replaced the code of procedures (which are using ref cursors) with SQL statements in VB with record set (i.e., RS.Open "select ...from ...where...",con) its working even in Development Environment.

Could you plz let us know what might me the exact problem.