MAX SONAR W1 - Accuracy

I'm testing the W1 http://www.sparkfun.com/products/9496 on a servo which pans back and fourth 180 degrees. The analog output doesn't appear to be very accurate.
I tried taking 10 samples, throw out the reading above 700 since I'm in my office and the room is not that big.
Readings above 500 for example are just well oustide the size of the room.

I read some posts on here but has anyone been able to "tweak" the accuracy of this sensor. Serial or pulse better?

Example readings
106 - 168
107 - 168
108 - 205
109 - 168
110 - 191
111 - 168
112 - 168
113 - 424
114 - 574
115 - 670
116 - 673
117 - 659
118 - 672
119 - 641
120 - 604
121 - 422
122 - 496
123 - 382
124 - 385
125 - 384
126 - 383

Can you post the code?

Maybe a little delay between readings to give the sensor time to recover?

Thanks for the interest.
I found the code here Arduino Playground - MaxSonar after I posted which is fairly good.
I added code to take five samples, I use the average.
It is better using the PW. Maybe it is not an issue. I noticed the PW is slowwer the analog.

Randy