This is a problem that has been in Quicken since Day 1. Quicken treats Treasury Bill purchases and sales are treated as capital gains rather than interest income. This is wrong from both a tax and investing perspective. I've attached a sample image of how a typical T-Bill looks in my account. If the "Bond Type" is "Treasury Bill" then any gain should be categorized as "Interest Inc" or "_IntInc" and not included in a Capital Gains report.
A related complaint: When quicken downloads the purchase transaction it put the T-Bill in the "Domestic Bonds" asset class and "Corporate Bond" bond type. Every time I purchase a T-Bill I need to manually fix that (as below) and need to manually enter the Maturity Date even though that information is in the incoming data.
The work around I have for segregating Treasury Bill interest is to create a Capital Gains report that only includes "Bonds" but that isn't completely correct as all bond transactions are included. I could make the Type "T-Bill" but that does not allow me to enter a maturity date which would mess up the "Maturity Dates for Bonds and CDs" report which I use extensively.
Maybe I'm missing something. If so, I'd love to be educated.