Hi Lou,
if you are working with JConnect 3 and you want to replace it with JConnect 4 you can try to follow the steps reported in this post:
http://www.webratio.com/forum/question-details/problem-accessing-mysql-with-webratio-6
Moreover you can check if the database Metadata provider supports the database's version. If you want to customize it you can refer to this article:
http://www.webratio.com/learn/learningobject/how-to-implement-a-custom-database-metadata-provider