But those problems are over, according to G for Games.
The new iPhone is now in its Product Validation Test (PVT) phase, which means it's just about ready for mass production, the site says, citing information found on Chinese social network Weibo.
Based on everything we've heard about a September iPhone 6 release date this would put the iPhone 6 right on schedule.
The info supposedly comes from sources within iPhone manufacturer Foxconn, where the production lines should be operating at full speed for testing purposes during the PVT phase.
It was posted by Xiang Ligang, a former professor at the Beijing University of Posts and Telecommunications and current CEO of the Chinese publication "CCTIMES," or China Communication Technology Information Management Engine.
The PVT phase means the factory will produce a small batch of new iPhones, the assembly line will be adjusted if necessary, and finally full production will begin.
The iPhone 6 has already been rumored to be in mass production, but it's possible that some sources mistook the PVT phase for the assembly lines running at full throttle.