I have a DLL written in Borland's BCB6 that we are using in VFP (both 6SP5 and 7SP1). The DLL itself is working fine (i.e. doing what it's supposed to do). The problem is that once we make any calls to the DLL, IMPORT FROM XLS/APPEND FROM XLS randomly crashes. In other words, someting about reading of XLS files in VFP6/7 is conflicting with the DLL. The conflict occurs in the form of spontaneously terminating the application (and on one computer causes a STOP error/BSoD). And the conflict does not always occur. Only certain XLS files trigger the crash (every time), while the majority work just fine (every time). When we rewrote the code to perform the APPEND first, then there was no crash. However, the application may stay running such that the next scheduled APPEND will occur after the use of the DLL, and this does cause a crash.

So, has anyone else encountered conflicts, either with importing XLS files or with the use of BCB/Delphi DLLs?