They sometimes work and sometimes they just don't.
Funniest thing is, there used to be a similiar bug in the past, a long time ago.
For a long time the bug mentioned in the above thread has been fixed and I haven't had trouble using Marauder's PS or the Orkulus' PS, even to jump itself if I'm playing Rebel.
However, Vorastra's PS just refuses to work. I repeatedly placed one behind enemy lines or in neutral gravwells and my ships (particularly, the titan) refused to use it to jump to another of my PSed planets. I can use the PS to summon the dark fleet alright, I have all PS-related reasearch done in the empire tree... but sometimes the PSs just don't work.
Fix plz, annoying!