Problem with FreeBSD using fwrite() function???

Firstly, thanks to all those that helped me with my "fooling the client into thinking php script is .jpg". I am using ForceType method to do that at the moment. My admin is looking into mod_rewrite for me though. Ok here's the problem. I made a script that logs the IP address of the client. $REMOTE_ADDR and it also takes a timestamp in UNIX format. I then split the 4 parts of the IP address... $ipsub = explode( ".", $REMOTE_ADDR ); This is then packed into a binary string... $LogLine = pack( "LS4", $TimeStamp, $ipsub[0], $ipsub[1], $ipsub[2], $ipsub[3] ); The timestamp is converted into a long unsigned integer taking up 32bits, and the following 4 parts of the IP address are converted into short unsigned integers taking up 16bits. That is then written to a file using: $fp = @fopen($LogFile, "ab"); if ( $fp ) { @fwrite( $fp, $LogLine ); @fclose( $fp ); } However, when I go to read the logfile and decode it using another script. It seems scrambled. Like the data didnt save properly. It decodes properly, reports the correct timestamp and ip address whern I try running it on my development machine (Win2k, php4.1.1). On my linux webserver it is also fine. But when I try it on my FreeBSD/php4.1.0 website, the results are not as expected. The IP and timestamp are way off. I have tried a little script to just pack the data, then unpack it, without saving to disk, and it works fine, so I know for sure it is a problem with the fwrite() function. Any ideas to why this is happening? Any solutions please? Im really stuck! Thanks Matt.