When upgrading from 1.0.5 to 1.1, a bunch of .jar files are left behind.

Directory: ...\webapp\WEB-INF\lib

Files:

atlassian-bamboo-api-1.0.5.jar
atlassian-bamboo-build-server-1.0.5.jar
atlassian-bamboo-charts-1.0.5.jar
atlassian-bamboo-core-1.0.5.jar
atlassian-bamboo-language-1.0.5.jar
atlassian-bamboo-license-1.0.5.jar
atlassian-bamboo-migration-1.0.5.jar
atlassian-bamboo-persistence-1.0.5.jar
atlassian-bamboo-plugin-autofavourite-1.0.5.jar
atlassian-bamboo-upgrader-1.0.5.jar
atlassian-bamboo-web-1.0.5.jar

This is easily rectified by deleting the old files and restarting the Bamboo service but I thought I'd write up a bug in case it's a chronic thing that will keep happening with subsequent upgrades.