These problems were brought up almost immediately after the question was asked, but the site was new, and nobody had authority, nor will to step on the toes of others, so a lot of discussion happened, and not a lot of action.
The problem is that the original question was very confusing, and was really about multiple questions. As it's worded now, I think the question is clear, but the title doesn't match it at all. More importantly, the answers don't match, to varying degrees.
I understand how, as @PeterTurner points out, the doctrine of Sola Scriptura can be confusing to a Catholic, thus leading to a confused question. But that does not justify a title/question mismatch. It does justify asking a question that needs to be clarified to be a good question.
I think my suggestion would be to close the question, then encourage the OP, or others, to ask the various questions that are present in this one question:
- What is the basis for Sola Scriptura?
- What is the basis for personal Biblical interpretation?
- Does the doctrine of Sola Scriptura preclude external assistance in Biblical interpretation?
Alternately, clean up the question to clearly ask about one of these sub-topics, and delete any answers that no longer fit (with the possibility to un-delete if the OP chooses to clean them up to match again).
EDIT: As it seems, once again, this question is generating discussion, and no action, I have now cast a VtC on the question. :)