username and password returns an empty response

[etalley]

In some cases (not all) the API will return a successful response with no API key, has anyone else experienced this?

the response is this:
<?xml version="1.0" encoding="UTF-8"?> <rsp stat="ok" version="1.0"> </rsp>

where a normal response would be
<?xml version="1.0" encoding="UTF-8"?> <rsp stat="ok" version="1.0"> <api_key>8c8c5ed092488fd0354b0d4421a</api_key> </rsp>