I don't have any NetScreen devices but I do have others like SonicWall - Nokia - Cisco Pix inside Orion and it is only the CISCO device which shows CPU and MEMORY graphs. I’m guessing Solarwinds developers find it easiest working with Cisco OIDs over these others, probably because of Cisco's bigger market and extremely strong support for their MIBs.
This caused me to resort to using Orion’s Universal Device Poller app for these other devices and you may need to use it for your own NetScreen devices.
Here’s the OID for NetScreen which I found in UnDP and it tells me Orion should work with NetScreen products: 18.104.22.168.4.1.3224
Once you try the OID for NetScreen you can build your own Gauges and Graphs - depends really on each OID and MIB results and how these are collected.