So it's got a tail spin were the tail is spinning left and nose right, that sounds like motor gain adjustment, I'm guessing at the LHS it had no tail spin?

I know with my Blade after flying the dog out of it I was losing power in one of the motors and developed a left tail spin. So I went to the book and looked at adjusting the motor gain to speed up the upper blades to stop it (The book go's by noise spin). I haven't played with the Comanche but the motors are inline and not side by side like the Blade. If you check out the Lama CoCo forums you should find info on this because the layouts the same or check the book. I'm not saying thats the Real Problem and adjusting the gains can be tricky so you my want the LHS to do the adjustments just to get it flying good.

When I got the blade I figured I would attempt adjustments or repairs my self before taking it to the LHS just to learn more before moving into the bigger Helis then use the LHS as backup if I just couldn't get it right (I've had to bite the bullet & do that some times).
It did help because I bought an hold Hummingbird V3 later on eBay that needed a lot of work and was able to work out the issues my self saving lots of money in the long run, now it's a steady bird to fly. Funny things effect these helis, after putting in new motors on my Blade I had some kinda tail hopping up and down. I asked the LHS and they said they didn't now what would do it. So for the heck of it I changed out the upper blades and it stopped. After looking at it I had blades from two diffrent packages because of running low due to crashes, so all blades aren't created equally after all.

Nav Lights, I made my on after finding some info on the net. Here's basically what I did. Went to Radio Shack and bought some LED's Pack of 25 for 3 bucks, one red flasher for 2 bucks and a pack of 1/2 watt omn's resistors for a buck. Stopped by the LHS and got servo wire and a couple of servo plugs for about 4 bucks. Soldered the stuff together to make a wiring harness and plugged into the 5th channel of the 4in1. If you start to go there check the net or let me know and I'll write down all the steps I took.

Hope this helped, Going to have a cup of joe & a smoke this early morning, Later Dude.

Crashing's cool it's something to talk about like the fish that got away but man it's expensive.