This is more for my benefit as a reminder of steps, but if you use Makecab.exe for your .wsp packages, it is important to install new versions that don’t step on old versions.  I keep old versions set to “No New Instance” and then New versions pick up the new version of the workflow.

New Version of Sharepoint workflow using a .wsp Package
Solution – add Solution folder “Deploy”
Add Manifest.xml (xml)
Add Solution.ddf (text)
1. Manifest.xml – change SolutionID using New Guid
2. Manifest.xml-change Destination Location folder to include version number.
3. Change Assembly version to next version, Properties, Application, Assembly Information
4. Solution.ddf – change CabinetNameTemplate
5. Solution.ddf – increment version on Feature Folder name (2nd name, leave first folder same since this is the source folder).
6. Feature.xml, change feature ID to new GUID.
7. Feature.xml- change Title to include version number
8. Feature.xml-Change Description to include version number
9. Workflow.xml –Change Name  to include [...]