I am having problems with file streams associated with the transfer from Borland C++ Builder v5 to v6. The situation is: I have a DLL applied to an ArcView application. A file called observation file has to be opened by the user in the application. But it should just be opened in case the associated "navigation file" situated in the same folder can be opened too and the header can be read.
The problem now is that the observation file can not be opened eventually due to an error "File can not be found!" with the navigation (nav) file (or the stream (fp_nav) that should be connected to the nav file).
The code is attatched below.
The value of the file stream (fp_nav) seems to be strange to me. It is a sequence of associated values like M_buf and M_constant_width, and some variables with question marks.
What can be the reason for not finding the nav file associated with the obs file (in terms of the same name, just different endings (.01o, .01n)).
The problem did not appear with Borland C++ Builder v5, it all worked fine.

FILE_STATE Rinex::Open_Rinex()
// Read RINEX navigation header & ephemeris data
RdGEphemeris(); // Glonass
if (!RdEphemeris())
return CLOSED;
else // Read RINEX Observation file header
if (!RdRinexHeader())
return CLOSED;
return OPEN;

bool Rinex::RdEphemeris()

char line[lineWidth]; // text line to read from file

STATE* svPresent; // flag for all present satellites
svPresent = new STATE[maxSVs];
for(unsigned int i=0;i<maxSVs;i++) svPresent[i] = OFF;

unsigned int version;

// ------- ** Read RINEX navigation header details ** -------- //
MessageBox(NULL, NAV_filename.c_str(),"File Not
return false;