I'm betting hidden fees within the trust are eating away the performance.
Before searching for bogeymen within the fund, I think the first step is to confirm whether or not the return numbers at the Quicken site are actually accurate. The fact that Morningstar doesn't have any return numbers at all makes me doubt the accuracy of Quicken's numbers, especially when they conflict with the fund's own prospectus.
I'm not sure if beltim's idea that the Quicken numbers exclude dividends is knowledge or speculation, but it seems like a reasonable hypothesis to me. The fact that the graph on that page is all screwy and it doesn't have any current price information also makes me doubt their data.
So my guess at this point is that it's a normally-performing S&P 500 fund with a 0.6% ER. Not great, but not as bad as the Quicken numbers make it seem. See if you can find any other source for its total return numbers.