Description:
------------
It appears that I found an interesting interaction between the simple_xml library and the mysqli_bind_param function.  The values contained within an XML tag are returned as simple_xml object, not strings (which is what I inferred from the Zend tutorial.)  This had an adverse side-effect when combined with the mysqli_bind_param function.  Please note that this may affect other functions/libraries as well.

The steps are as follows:

1. Copy the value of an XML element into a variable.
2. Use the element in a prepared mysqli statement, binding it to the statement as a string.
3. Run the query.
4. Repeat steps 2 and 3, possibly with a different query.

After the bind or perhaps after I was done with the query, the actual data was changed from a simple_xml object to a very odd looking string.  This would crash the apache web server approximately 80-90% of the time when accessed.

Original variable data:
["username"]=>
object(SimpleXMLElement)#3 (1) {
  [0]=>
  string(4) "test"
}

Modified variable data:
["username"]=>
string(64) "a94a8fe5ccb19ba61c4c0873d391e987982fbbd3                        "

Reproduce code:
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No code provided since it is being developed for the company I work for.