I feel like I'm missing something obvious. I've taught a number of horses to lunge/long line, I drive on a regular basis - ground and in a carriage. BUT...
I just started getting my mare to ground drive. Our first 'session' went incredibly well, it took her about 5 minutes to figure it all out. She knew how to give to her bridle before - and had been made accustomed to the surcingle, so she really only needed to connect all the dots.
The first time I didn't have any good long-line so I connected two of my reins, which both had quite heavy clips that pulled on her bridle (indian hackamore) - which she tolerated quite well until I tripped and yanked on her face >.< I was so focused where her feet were I forgot where mine were. After that she started tossing her head when I asked her to woah. So I practiced some woah goes (with as tiny cues as possible) and when she stopped head tossing at the woah I stopped.
Sooo... then we moved the very next day, and a week went by of getting used to our new world, then a week where she's been sick. She's still getting over being sick, but she does need some exercise so I decided to try again. It went Horrifically!
She just would not walk out straight, she would turn both directions but only with a hissy fit, she would halt and walk again but would NOT walk straight! she kept zig-zagging and wiggling and turning back around to face me, despite me pulling the opposite rein. Then I realized it was a problem with walking through one corner of her field, she's apparently scared of that area now, there was a ground hog there the other day, so now it's horrifying. So I hand walked her through it a number of times. Once she was over That issue I tried again, she would drive through it but only while jigging and dancing around and trying to turn back toward me and just plain old fussing. The only tack difference is that I got a lunge line and put light weight clips on it, so there was no more heavy clips pulling on her face.
I feel like I'm missing some obvious reason for this- but this has never happened before, they all walk out straight, it's the turning that typically stumps them (at least the horses I've worked with). I appreciate any ideas - I think I just need too look at it from another angle.
P.S. she was very upset about bugs and not feeling great, so it could have been she was just Not in the mood. But that's not really a good enough excuse to throw hissy fits about me asking her to walk quietly around her paddock - to me at least. I wasn't asking her to work at all more than what she was doing anyway.