Errors with urlencode and gzcompress

Hello all, I am having some trouble figuring out how to pass data to a remote PHP script. Here is the scenario: I have several Windows boxes running Apache 2 and PHP 4. PHP5 is not an option because of some Zend Encoded scripts that we purchased. I need to pass data from one script to a remote script. The local script has an array that is serialized. Then the serialized string is then double urlencoded. A single urlencode does not work correctly on PHP4/Win32. The serialized and urlencoded string is then passed in the request to a remote script: http://192.168.1.2?data=<serialized string> This process works fine for small amounts of data. If the URL is below a certain limit (maybe 1024 characters, have not yet found the exact size limit) this works fine. I now have a need to pass more data to the remote script. I have tried to do $temp = array ('lots of data...'); $temp1 = serialize($temp); $temp2 = gzcompress($temp1); //compress our string first to save space $temp3 = urlencode($temp2); $data = urlencode($temp3); http://192.168.1.1/?data=$data Sometimes this works and sometimes not. I have not yet been able to figure out why this sometimes fails. Can anyone tell me why this works sometimes and others not? Or can someone suggest a better way of passing data to a remote script. Thanks, James