It has been pointed out to us that the bicubic image scaling hint that we use in Confluence 1.2.1 is in fact ignored by all JDK's prior to version 5.0. The sole exception is Mac OS X. As such, customers upgrading to 1.2.1 will only see increased thumbnail quality if:

1. You are running Confluence on JDK 5.0 (not recommended, since it's still a pre-release, and we haven't tested Confluence in this configuration)
2. You are running Confluence on JDK 1.4.2 on Mac OS X

We apologise for the error.