Why does {{ user.getPhotoUrl(64) }} point towards storage/runtime and not to storage/userprofiles?
I don't think the /Applications/MAMP/htdocs/craft/storage/runtime/assets/sources/ log entries are related to the request when getResourceUrl() is called.  Of if they are, they are elsewhere in the request and not as a direct result of calling getResourceUrl()`.

The error in the console seems like the one to investigate.  Based on net::ERR_CONNECTION_REFUSED, I'd check to make sure that craft/storage is recursively writable by PHP as a starting point.