Unfortunately I don't know anything about ColdFusion, so I am not sure why the JDBC drivers are not working. I do know that the jdbc-odbc bridge is significantly slower than the SQL Anywhere JDBC driver though. Have you tried the ColdFusion forums? If you find someone with ColdFusion knowledge, I can help with SQL Anywhere knowledge to perhaps solve the problem.
Maybe the connection cache needs to be bigger? Also, if it is not very smart, database connections could time out if they weren't used very often. To prevent this you can turn off the connection timeout (set the IDLE connection parameter value to 0 in the connect string/datasource)
--Jason