?
We actually haven't tried using SBT just yet (in fact, I just learned about it from your post).
But generally speaking, one of challenges with Maven is that it's convention-based, and doesn't have any documentation on the convention. So it's possible that SBT is using a slightly different convention than Maven or Ivy clients are. Moreover, different "packages" have a convention to behave differently...
Would you able to attach Fiddler and see where some of the discrepancies in the request/responses might be? Sometimes it's incredibly obvious, and that might allow us to implement yet another undocumented convention. It may be easier to communicate over email, so perhaps fill out a ticket or just email us at support-at-Inedo-com once you have some details?