What charger are you using? Make sure the Flex option is turned off. I suspect you've sort of ruined your gp3300 if it's peaking this high. Normally, nicads loves being flexed but nimh hates that and you can probably kill it in one charge.
Here's what you need to do:
1. let it rest for a few days.
2. using a tray such as Intergy Octane 2, bring it down all the way until the lights goes out.
3. let it sit for another 20 minutes so the pack is recooperating. Making sure your pack is not hot nor cold. It should ideally be at room temperature or slightly higher say around 82f to 86f. Don't ask my why because I'm not allow to give out the secret behind this.
4. borrow or charge it on a charger that is designed for nimh and set the peak detection to .03 ONLY! preferrably a turbo 35 GFX. Also get a temp gun and make sure your packs are between 145f to 155f.
5. wait 10 minutes and discharge it at 30 amp down to .90 or 5.4v per pack because yours are teh 6 cell pack.
Considering if you have not yet killed your pack, this is how it would be to re-train the pack to get back on track. If worst scenerio and you're still getting a high peak then chances are, you've ruined it. But........ rest assure, send it back to us and we'll take a look at it to see if we can fix it for you or re-train it with our CET system.