Thank you for your e-mail about civil disobedience.
As I have said in my article on the subject, we are to obey government (Romans 13). But that is NOT an absolute command. If there was never a time when we would disobey government, then government would be God.
So the key question is when do we disobey government. I believe that the Scriptures teach that we obey God rather than man (Acts 5:29) when there is a direct, specific command given by government that would force us to disobedy a direct command of Scripture. The Bible provides cases of this in the Old Testament (Hebrew midwives, many instances in the book of Daniel, etc.) and the New Testament (Acts 5).
The historical cases of Corrie Ten Boom, Rosa Parks, and Martin Luther King would all fit as examples. Erwin Lutzer (Measuring Morality) and Norman Geisler (Christian Ethics) deal with the issue of civil disobedience and obedience to Scripture in their books, if you would like to read more on the subject.
Your question about Romans 13 is more difficult. I take it that the Apostle Paul is giving a general principle rather than a universal pronouncement. Usually it is the case that "rulers hold no terror for those who do right." But that is not always the case. There certainly are (and have been) tyrannical leaders.
It's instructive, though, that Paul says this at a time when a corrupt leader (Nero) was in office. If nothing else it should remind us how much worse government leaders can be. Nevertheless, we are to obey those in authority (Romans 13) and pray for those in authority (1 Timothy 2). Just as there are exceptions to total obedience (civil disobedience), so there are exceptions to leaders who "hold no terror."
I might also encourage you to revisit my article on the Probe web site (www.probe.org/docs/civildis.html) and a recent Breakpoint commentary by Chuck Colson on "Caesar and Christ" (www.breakpoint.org). I hope this helped a bit. God bless you.