The following snippet:
0000001d SystemOut O 2007-12-06 08:11:34,499 FATAL [server.startup : 0] [atlassian.confluence.setup.
ConfluenceConfigurationListener] contextInitialized An error was encountered while bootstrapping Confluence (see below):
org.apache.commons.logging.LogConfigurationException: org.apache.commons.logging.LogConfigurationException: Class org.apache.commo
ns.logging.impl.Jdk14Logger does not implement Log
Occurs in Confluence 2.6.2 .war installation on Websphere (and possibly other environments). This has been reported by a customer, but not yet replicated by Atlassian.
Solution was to replace commons-logging-1.0.jar with commons-logging-1.0.4.jar (which comes with confluence 2.6.0).