I have tried hard coding the file name and path and get the same results, I have tried the following:
$astfile = 'c:/FTP_Scripts/xml-ast-convert/NYPH-20101101-210000.ast';
$astfile = "c:/FTP_Scripts/xml-ast-convert/NYPH-20101101-210000.ast";
$astfile = 'c:\\FTP_Scripts\\xml-ast-convert\\NYPH-20101101-210000.ast';
$astfile = 'c:\FTP_Scripts\xml-ast-convert\NYPH-20101101-210000.ast';
all of these fail the same way