Is there a delay in creating the list?
Here are the steps I am doing:
1. Create list
2. Create Campaign.
3. Schedule Campaign.
Sometimes this works and sometimes it gets to step 3 and then I get a Bad Request.
I have tried using my XML in the REST Client and I get \
Error 400: No contacts to send.
Even though when I log into constantcontact.com I can see the campaign and it has a list with 2 subscribers associated it.
There should not be a delay in creating a list. You should not be getting that error unless you are trying to schedule to an campaign that has lists attached to it but no contacts in the lists.
I tried recreating this issue on my end, but it does appear to be working fine. I would like to have you email us your code so that I can see what is going on, with that I may be able to find a solution.
You can email your code to the webservices support team.