If you are using Internet Explorer 6, upgrade immediately to a newer version.
Internet Explorer 6 uses a cryptography protocol called SSL 3.0, which has just been found to be vulnerable to attacks trying to intercept payment and cardholder data.
Merchant Warehouse will require to disable SSL 3.0 on or before December 1st.
To disable SSL 3.0, follow the instructions provided by this link:
You should also read this blog post from Merchant Warehouse:
Support for Internet Explorer 6 has been discontinued by Microsoft. That means that it is not receiving security updates.
If you continue to use Internet Explorer 6 you may not pass your upcoming PCI security audit.
If you are using Internet Explorer 6, upgrade to a newer version immediately!