Mysql-php3-apache problems...I'm lost

Sorry, this problem has me stumped....I generated 18 files from a dbf file on my machine with 3k records in each file in php format to load into a mysql db at my web site. 56k records total, more or less. The same script generates each file, reading the material directly from the dbf file on my machine...the script uses a while loop and just keeps making files and generating new files names as it goes along until the script reaches the end of the dbf file. I upload the files to my site and run them from my browser....z1.php3, z2.php3 etc. The problem is that three of the files generated an Internal Server error from apache, when I looked at the error log I saw the error message below. If all the files are identical, php code, passwords etc ( except of course for the data itself) and generated from the same script... why am I getting internal server errors and the message below on some files. I can't even figure out where to begin to look for an answer...about 48k records actually made it into the mysql. any help appreciated. "Premature end of script headers: /u/httpd/cgi-bin/php3.cgi" ken