"Unable to locate JAR/zip" error for JDBC connections [BIRT Eclipse, Windows 7, Oracle 11g]

I had similar issue. Clicking "Clear all" and then adding the jar manually solved the problem.

The answer in this case was unfortunately stupidly simple -- after closing and reopening Eclipse, I had no trouble removing the driver, adding another, and getting to work. I was up and running in no time.

Thanks for all your help!