We heard back in June that the iPhone 3G would not be offered with an optional tethering plan but now a new report indicates that might only be half the story. It now appears that an iPhone 3G tethering plan is back in the mix and is being considered worked on at AT&T. What’s the big issue with a tethering plan that’s causing all this ruckus? It is now being reported that an insider at AT&T is citing network stability issues as the reason for the delays. Of course AT&T customers using a variety of other smartphones have access to tethering plans, but the source cites the enormous number of iPhone users as a potential problem. Apparently Big Blue isn’t overly confident and fears that its network might buckle under the added stress of iPhone 3G tethering. What’s kind of sad in all this is we doubt even 5-10% of iPhone 3G users nation-wide would opt for a tethering plan. If network stability is indeed the issue, it’s a sad state of affairs when the gradual adoption of a tethering plan by such a small percentage of iPhone users would throw things out of wack.