It can't fail. It doesn't have an accuracy check, it will always reliably apply so long as you have an upgraded henchman selected.
What you may be experiencing is an issue of lag, where the upgrade icon doesn't appear next to the henchman in the pet window. Was very common in the US Beta.
Check your henchmans costume, it will have changed to show the upgrade. Grave Knights get more armour, Zombies get noxious breath.
Oh, and Ghosts can not be upgraded - they come with all their powers from the outset.
I've found that the buff icons for the pets don't refresh properly, some times it seems they only refesh when a new buff is applied. Maybe that's what you're seeing?
IN MEMORIUM OF GAYBABY
CRUELY TAKEN FROM THIS WORLD WHILE SO YOUNG
The ghost definitely took an upgrade too as his costume changed from the normal skinny naked bloke to one with armour and a helmet with two horns. Pity I didn't take a screenie but I didn't imagine it - well, wasn't drunk or otherwise intoxicated anyway! 
Wasn't experiencing any lag at the time and must have tried it 20 - 30 times. Definately failed a couple of times on the vombies as well, again with no lag experienced in the entire mission.
The pet status display is bugged, the upgrades/buffs do effect them, they just cant always be seen.
That was a big waste of endurance then! 
Thanks for the info. Going for a trawl on the US boards now...
Think I've worked out why the graphics were different - you get a different ghost from different fallen minions so in the case where I saw different graphics I must have raised it from a grave knight rather than a vombie.
The graphics and strength of your soul extraction pet depends on what minions corpse you use to summon it from.
Going to try this tonight anyway but does anyone know if you can dismiss a zombie/knight/lich and use the corpse from that to get a ghost?
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Going to try this tonight anyway but does anyone know if you can dismiss a zombie/knight/lich and use the corpse from that to get a ghost?
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If you can then it's an exploit. Plus, you'd probably have to use /releasepets as /petcom dismiss leaves no corpse to use the power on.
is the ghost power worth getting then?
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is the ghost power worth getting then?
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Yes - look up my Upgrades and Powers thread - they get a Hold (Necroplasmic Grasp) out of the box, as well as decent resists, flight and other nice toys.
And it looks good
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Going to try this tonight anyway but does anyone know if you can dismiss a zombie/knight/lich and use the corpse from that to get a ghost?
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If you can then it's an exploit. Plus, you'd probably have to use /releasepets as /petcom dismiss leaves no corpse to use the power on.
[/ QUOTE ]Yup, you have to use releasepets. It's useful at the start of a fight though, summon lich, release, summon and buff other pets, then summon lich after it recharges.
Anyone had their upgrade minion power fail? I find it occasionally fails on my zombies and knight but last night I could not upgrade my ghost at all. I know it's possible to upgrade the ghost as it worked just once (and looked very nice too!
).