Conclusion after talking to TurboTax support:
They claim (without providing any evidence) that the problem is NOT that page 1 of Form 4684 was missing from my Federal and California returns. Rather the problem is that page 2 of Form 4684, which was included in both Federal and California returns in Forms Mode and when printing, cannot be included as part of efiled California returns. The only remedy is to file California by mail. They offered to refund my $25 fee for California efiling.
However this leaves me dissatisfied on several accounts:
1. Why can't Form 4684 be efiled for California returns? having to print and mail is a great inconvenience and delays my refund.
2. Why doesn't TurboTax make this clear to me BEFORE I attempt to efile? It might have been possible to avoid the problem if I hadn't already efiled my federal return and didn't want to amend it.
