I have the same issue as gc32. My K1 contracts and straddles are showing up on Form 6781, but the Section 1256 Contracts reported on my 1099-B from my broker are NOT showing up on the 6781. I suppose I have to manually enter them.
This, along with Taxable Accrued Interest from Bonds, which is also not being imported from my 1099-B is causing me to have to go through all the numbers in detail and manually enter what is missing. This is rather annoying when the data is on the 1099-B
