I have the same problem with Core 05 (the trading station that I have to get the Scarab pilot to is an Assassins Guild station in Core 05... which, even without the instant exploding is quite the problem

), I think the planet is simply placed too close to everything. Or that's what I'm guessing.
I had something rather irritating happen to me after I acquired the Leviathan- I was just tooling around in Thuruk's Beard and was on my way to redock at the Levi when its reactor went critical and it blew up. Thing is, this is an Argon-built Leviathan that I bought from their shipyard, not an RE attempt. What gives?
Have to applaud the Levi's firepower though- most things take around ten minutes or so to get a Xenon station's shields down, it managed it in one or two

Also, upon entering the sector, there was a K and three J's plus fighter escort, P's, and a Q- P's, Q's, K's and J's went critical easily within a minute.

My shields dropped to around 1/3. Pretty decent superweapon.