We use Veritas for our failover environment and have ran into problems. The biggest is when we configure a gateway between brokers. We configure the gateway with the DNS name of the server, webMethods goes to the server and resolves the actual name of the server. When we failover to our backup server the gateway is pointed to the failed server. This means when ever we run into a failover situation we have to make changes to the gateway to point it to the failover server.
We also had some problems with logging but were able to solve this with some help from webmethods Support and our UNIX guys. We were only logging when connected to one of our servers if the server failed over the logging stopped. If you want more detail on this I can have one of the people involved with this put more information out for you.