When does VA stop giving negatives? (in General)

I forgot to learn VA on my enchanter when i had tons of XP, and put it all into EC... then when i got 14k XP, i learned a VA, forgetting that at a certain lvl, massively lower than damage inflicted, it makes your minion absorb negatives...
Just wondering at what point it stops doing this, if anyone knows, so i know how much XP to save before retraining, as i need the VA ASAP, I don't want to have to unlearn it again, and i don't particularly enjoy my minion drawing "strength" of negative 80-100k... :P

DOH...

I'd try when you have enough to match maybe 10 percent of damage done...

hehe, I'm almost up to enough XP to match 1%. at this rate, it'll be 4-6 days :P