I use https://www.salesforce.com/services/Soap/u/22.0 for testing with my account, sandbox should work same. Note that Teiid version is at 22. You can try https://test.salesforce.com/services/Soap/u/22.0
Also we would need more information than "import error", post the whole stacktrace to see where the error happening?
Changed to 22. The import error went away. But was not able to query any tables from the Sandbox, The query just hang in SQL workbench.