The original post is a bit old but people are likely to look at it for an answer to this question.

Every state has a statute that says if you "are transacting business" in the state you need to register as a foreign corporation. Any corporation can only incorporate in one state and registers in others as a foreign corporation.

Every state also has exceptions to that rule and what transacting business means.

For instance, owning property, appearing in court, forclosing on the property, etc. is not transacting business. Sending things in interstate commerce into the state is not transacting business. Sending things into the state might though trigger the state's long arm jurisdiction if you are sued there.

Checking opinions of the Secretary of State and case law on the subject in your state would probably clear it up. Also the AG of every state issues opinions that might cover that.

For example, in a recent case in FL, a WI engineering firm did engineering drawings for FL contractors. They sent inspectors into Fl to check the engineering work re the plans, etc. The engineers were licensed in FL. That was ruled NOT to be transacting business in FL. Neither did the licenses make any difference.