Quicken Internal Rate of Return IRR?

Quicken uses the IRR for it's calculation for valuing investments. They warn against using it for investments under one year old. I am not sure I can see why it is not a good measure for investments under one year old.

Can anyone help me understand why this should not be used for investments under one year old? What should be used?

Since IRR is the rate of return that equates the Net Present value of cash inflows equal to the Net Present value of cash out flows, for one year the IRR need to be very high or the rate of return or cash flow should be very high for this to happen, which will be impossible in the practical sense. For example if you invest x dollars and the one year cash flow is y this y should be close to x to get an IRR equal to X, such projects that pay back in one year is hard to comeby and the discount formula may not converge.