memory leaks with Flex?

Hi,
I have been interested in starting to use Flex, but I have also seen some posts on Alex Harui's Adobe Flex blog with some complaining that their Flex 2 applications have memory leak problems. I also saw on stackoverflow.com that some feel that these problems have gotten better with Flex 3. I suspect that a fair number of memory leak problems are due to programmer error rather than with the Flex components, but could any of you comment on what you have found with respect to memory leaks with Flex?