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.

<?php
// Code to illustrate bug #39299
// Differences in XSLT's are at lines 56/57
echo 'pHp '.phpversion();
$xmlDom = new DomDocument();
$xmlDom->load('http://scs.gmu.edu/~rgomez/qc/xml/gmu.xml');
$xslDom = new DomDocument();
// Comment/uncomment lines below to select XSLT file
$xsl = 'http://scs.gmu.edu/~rgomez/qc/xml/gmu_program_schedule_bug_fails.xslt';
//$xsl = 'http://scs.gmu.edu/~rgomez/qc/xml/gmu_program_schedule_bug_works.xslt';

echo "<p>Using $xsl</p>";
$xslDom->load($xsl);
$proc = new XsltProcessor();
$xslDom = $proc->importStylesheet($xslDom);
$outputDom = $proc->transformToDoc($xmlDom);
echo $outputDom->saveHTML();
?>

I don't even know, what's your expected output and I'm not in the mood (nor do i have the time) to analyse your xslt.

Please provide a as small as possible script/xslts and tell me, what your expected output is and what you get.

But at the end, I doubt it's a php issue, but a libxslt one, so you may better go there directly (try with the commandline tool xsltproc, if you get the wrong result there as well, it's defintively not a php issue...)

I guess we're both individuals with little time and varying moods. Agree it's actually likely to be a libxslt problem, I may try to report it there. 

If someone else ever reports something like this not working:
<xsl:key name="my-key" match="$my-var" use="my-element"/>
you know where it comes from: can't use a $variable in the match="" attribute.

Have a nice day/night and thanks for making pHp such great product.

I close this bug for now, as it doesn't look like a php issue.