I am trying to use two datasources representing two different connection pools in the same transaction. I locate each datasource using jndi, get a connection, and then try to do some updating. When I try to get the second connection, I get a message stating "Connection has already been created in this tx-context. Illegal attempt to create connection from another pool". If this is true, then is'nt this a huge drawback that Weblogic 5.1 doesn't support multiple connections(multiple pools from different databases) to participate in a transaction??

Yes that is big drawback of web logic

I guess you are using JTS implementation. Using a pool driver rather than JTS driver should solve the problem.