I have just successfully tested Cuelux 0.25 on Ubuntu 9.04.
I have installed it using the following steps:
- download the release from http://www.cuelux.com/downloads/
- right-click the downloaded "Cuelux-0.25.1-Linux-x86-Install" file to Properties->Permissions and enable the Execute checkbox
- double click the "Cuelux-0.25.1-Linux-x86-Install" to execute and follow the instructions on your screen
- start the Synaptic Package Manager to install the packages listed above
- go to Applications->Cuelux and start the Cuelux program