Yakima rack problems

Is anyone having issues with the new model ('04-'07) Prius and using the Yakima rack with Q towers? I'd been using my rack successfully since Nov of '06, but last month during a biking vacation to Colorado, my Yakima rack came loose and couldn't be resecured to hold two bikes. The rack wouldn't mount up tight and the towers would not lock down.
After 5 hours of working with it and talking with Yakima (getting further instruction, the proper dimensions, etc.), we had to dismantle the rack and put it and the two bikes inside the Prius along with our luggage (talk about a nice commercial for the Prius!) I had successful mounted and removed the rack three other times before this. I've used other Yakima towers on other cars for 16 years with no issues.
Yakima says they are using different front clips for the Qtower on the new model Prius and are sending me a couple, but they haven't arrrived after 3 weeks.
I had taken several short trips (< 150 miles) with one bike, several very short trips with 3 bikes all with no issues, but had not done the 75-80 mph thing with two bikes for several hours before.