I'd recommend opening a ticket with NSP support if you haven't already, and we can send you the latest version we have.
I uploaded the signature and I will apply now.
Just to confirm, the correct signature is "UDS-SSL: OpenSSL TLS DTLS Heartbeat Extension Packets Intormation Disclosure III", ok?
They have their UDS emergency signature:
"The new name is “UDS-SSL: OpenSSL TLS DTLS Heartbeat Extension Packets Information Disclosure IV”. "
As well as an emergency signature set:
0x45c04400 - Name: "SSL: OpenSSL TLS DTLS Heartbeat Extension Packets Information Disclosure Detected"
There has been an update to the UDS since the 3rd version, the latest version can be found at KB81648. There was also the release of a signature set containing a Heartbleed signature, I would recommend using both the latest signature set and the latest UDS together for the best detection.
The link to KB 81648 can be found in my previous post which explains/suggests what you've just mentioned.