Hi Simon,
there are some regarding this dashlet, if you have mgcp-only gateways/routers configured:
Trunk utilization graphs are not working: CSCuj53117/CSCuj34579
Cisco Prime Collaboration Assurance did not support setup where MGCP without H.323 was configured on a VoiceGateway.
and...
Top 10 utilized trunk dashlet shows "null" for mgcp serial interface: CSCuh73198
It should be fixed in next patches.
At the other hand, I have missing dashlets observed in case of using a not supported browser version.
PS: Do you see the SR1 (PCAssurance-appbundle-9.5.0.38292-1.x86_64.tar.gz)? There are many other bugs fixed. It was released at 3rd Oct.
HTH, greetings, Chris