Xarchiver hammering the CPU

[Swaphead]

Running 64-bit Sparky 4.2 LXDE on an old dual core machine.
I was using Xarchiver to join some RAR files together - the temperature shot up,the CPU monitor in my panel was showing all green, while the Task manager showed 50% so I thought - aha! - it's only using 1 processor.
I looked up an old post on the forum (how to tell if Sparky is "seeing" all the cores - it seemed fine)

I put in an old disk running Lubuntu 14.04 which joined the files no problem, and realised it was using file-roller.
So - back to Sparky - install file-roller - works perfectly. Problem solved (kind of)
Anyone else had a problem with Xarchiver, out of interest?

[pavroo]

It's strange...
I've been using Xarchiver for years and newver seen something like that.
But I will keep my eye on it now closer.