Sites that use Java are causing NTLM authentication prompts due to a known fault in Java 7.
When accessing websites that use Java, you are receiving NTLM authentication prompt pop-ups.
Check the version of Java you have installed on your client machines as there is a bug in the Java 7 software with handling NTLM v2.
This is not a Smoothwall issue. This is a bug in the Java 7 software that causes the NTLM prompts per the following help threads:
This issue is resolved in Java 8.