Recap for the lurkers: you're seeing a bunch of generalblock-0 's when you set the position of a view; this post suggests it may be a bug in Instruments, not a bug in Quartz:
Thousands of new 0 size objects being added to my net total every second, should I be worried? - Stack Overflow
Apple suggests that if you think you've found an error in their memory management, check it with the Memory Monitor instrument:
https://devforums.apple.com/message/88251
