Great! I am glad it worked -- did you just adjust the soft start resistor and capacitor? Sometimes you have to ramp up the dc voltages for the IC to kick in. There is an option in LTspice to ramp the sources. By the way, since you are using LTspice I should mention a few things.
1. There is a very nice LTspice Yahoo! group that you should consider joining (if you have not done so already). The people there are very nice and the original developer of the software read the group as well (Mike Engelhardt) -- he is extremely knowledgable. I have not visited the user's group in a while but in the past they have been very helpful.
2. Download this file from Linear Technology h**p://ltspice.linear.com/software/handout.zip
This file contains lots of material including a presentation on LTspice made my Mike. It also includes a directory called "jigs" which has a test circuit for nearly all of the ICs that Linear Technology makes. In most cases, the circuit that is setup in these "jigs" or test setups is the example circuit that is mentioned in the datasheet. So you may find this extemely useful to get a circuit simulation started.
Best regards,
v_c