wow, you guys are awesome. i really appreciate the help, in that the boots are expensive, so i'd like to make them work.
the boots were fit a number of times. my foot size is a women's 8.5/39, or men's 7ish. the boots are a size 25. my shell fitting was done by the shop where i got them, and they spent a lot of time with me, and i'm pretty confident the shell was fit properly. as i do not have the boots with me (they are in storage for the summer as i am at another job), so i cannot say the exact mm measurement. but i remember when i put my foot in the shell, and the guy from the shop stuck their measuring rod behind my heel, that was all the room there was.
i am 29, 5'6", 130 lbs. i am an ex-division I soccer player, so i have worked with my feet quite a bit. my heel cuff is slightly narrow, and grows wider towards my ankle. as an athlete, i had my left ankle redone when i was 19.
the blisters are on my heels (both of them). they show up when i ascend only, and i cannot feel them when i descend (unless its a really big day). i buckle the bottom two buckles when i ascend to the point that my foot can cramp, but it gives a slight bit of relief to my blisters, so the cramping is worth it (it feels like i'm breaking in a pair of hockey skates).
i am a yoga instructor, meaning quite flexible, and i have a pretty good ROM in both feet. my ankles are skinny just like any other athlete, and i've got some calves on me, but nothing too crazy. my foot in general is fairly normal. i pronate outwards a bit (hence the ankle reconstruction... multiple ankle sprains).
my biggest concern is that i tried everything i could last season, so i'm hoping that someone out there might have one more suggestion. i really like how the boots ski, and hope to fix this problem. i hope this all helps.
again, thank you so much for taking the time to help me out. its greatly appreciated.