Thank you for this bug report. To properly diagnose the problem, we
need a short but complete example script to be able to reproduce
this bug ourselves. 

A proper reproducing script starts with <?php and ends with ?>,
is max. 10-20 lines long and does not require any external 
resources such as databases, etc. If the script requires a 
database to demonstrate the issue, please make sure it creates 
all necessary tables, stored procedures etc.

Please avoid embedding huge scripts into the report.

Code to test:

<?php

// To test this, you can use CSV file in this zip:
// http://spatialkeydocs.s3.amazonaws.com/FL_insurance_sample.csv.zip
$csv_file_content = file_get_contents("sample_file.csv");

$temp_file_name = "php://temp"; // when replaced with actual file name, everything works
file_put_contents($temp_file_name, $csv_file_content);

$handle = fopen($temp_file_name, "r");
$line = fGetCsv($handle, 1000, ",");

var_dump($line); // in PHP 5.5.8 returns echos bool(false)

?>

Opening php://temp will get you a different stream each time. If you want to use a temporary stream like this, open it for reading and writing, copy the contents of the stream you want into it, rewind, and begin reading.

Note that to read CSV data you don't need a temporary stream in the first place.