filepro() is apparently expecting the map file to be lowercase (at least on UNIX-like systems).
(PHP 4, PHP 5 <= 5.1.6)
filepro — Read and verify the map file
This reads and verifies the map file, storing the field count and info.
No locking is done, so you should avoid modifying your filePro database while it may be opened in PHP.
Note: When safe mode is enabled, PHP checks whether the files or directories being operated upon have the same UID (owner) as the script that is being executed.
The map directory.
TRUE on success or
FALSE on failure.
Two notes here:
1) PHP does not need a running copy of filepro to read the datafiles. Just provide it with a directory containing the map file, key file, and the data* file(s) for the table you want to read. Screen files, outfiles, and process files are not used.
2) This function seems to pass back the system error code in brackets  along with the PHP warning. A list of error codes can be found in your filepro manual's appendix.