On Aug 13, 2011, at 11:33 AM, art wagner wrote:
"The possibilities of the particle and the event horizons as the IR cutoff length were subsequently discussed by Li[16], who found that apparently only a future event horizon cutoff can give a viable DE model."'
[16]  M. Li, Phys. Lett. B 603, 1 (2004). 

That's what I have been saying!  I never read Li.

However: "All models with a future-event-horizon cutoff suffer from the drawback that, although they may fit the data, they cannot reproduce an early matter dominated epoch."