AD8065 Spice model "VT0 out of range"

I'm trying to use the AD8065 spice model in a simulation with QUCS, but cannot seem to get it to work -- when I run the simulation, it throws the following errors:

checker error, value of `Vt0' (0.13) is out of range `.0,0]' in `JFET:J1'

checker error, value of `Vt0' (0.13) is out of range `.0,0]' in `JFET:J2'

I've spent a few frustrating hours unsuccessfully googling to figure out what is going on, so any help is much appreciated! I've attached the netlist for a simple unity-gain follower using the AD8065 for reference -- the offending lines are #41 & 42.

Thanks,

Neal