I've recently got new Nike zoom elite 7 and Nike lunar glide 4 and both trainers of both pairs are squeaking when I run in them (just done a few 8-10 mile runs in each so far)......anyone else had this issue? Hopefully something to do with them being new and will 'wear' out soon but never had this with other Nike trainers over the years. As it is with both trainers and both pairs then would be too much coincidence for me to have burst air unit on all 4 shoes,