Actually there are several known issues like this, however the one he is getting is directly connected to his upgrade so re-imaging will not fix the issue. There was a bug causing the restarting of processes over and over again in 4.1r2 and was fixed in 4.1r3 and all subsequent code releases. These are two separate issues. We saw that when IDPs were upgraded to 5.x code that the processes would restart constantly. The fix I gave should resolve the issue without you having to re-image the IDP. I have done it many times.

Also there could be other issue with that box. Take a look at the techsupport.
Here is how to get run the tech support scripts:
Log into the IDP as admin
"su -"
put in roots password
Tech Support without core files:
"sh /usr/idp/device/utils/tech-support"
Tech Support with core files:
"sh /usr/idp/device/utils/tech-support -c"
Core files will need to be analyzed by Juniper's engineers so you will need a case with JTAC and have the case escalated to ATAC. The only caveat here is that this is a Demo box. If you have core files then don't waste your time putting in a case with JTAC as they will just have you re-image the box anyway and put the 4.1r2 code on, then upgrade to 4.1r4 or 5.0r2. Most likely the 5.0r2 as the 4.1r4 is going to be EOL soon.
As a side note:
Whenever you get a demo box it is always good practice to re-image the box as the images get destroyed by previous users and the IDPs are not always re-imaged.
Enjoy!