Julie,
We actually just recently figured out what was happening. It looks like there was a minor bug that was looking at the pipe data lists a little differently when using VIH rotors. We have it scheduled to be fixed by tomorrow and a part of the next release later this week.
In the meantime, you can work around this by performing the following steps:
1- Open your pipe data and go to the mainline pipe data tab
2- Change your pipe class to match the Lateral Pipe class (in your case, change to class 200)
3- Adjust the pipe sizes to match what you would like the mainline sizes to be
4- Change the mainline class back to what you initially wanted (back to sch. 40)
5- Resize the mainline again and all pipe labels will change appropriately (just make sure to open your gate valves as needed)
Thanks for your patience, and let us know if you need any further help with this.