If Dreamweaver crashes during site cache rebuild at start up, here are a few things you could do to solve the problem:
1. Undo the latest code updates you made to the site that you are currently working on
2. Rename/move the cache folder (usually in C:\Documents and Settings\[user]\Application Data\Macromedia\Dreamweaver MX 2004\Configuration\SiteCache)
3. Rename the folder of the site you are currently working on

Once you could open up Dreamweaver without crashing, try rebuilding site cache: Select Site > Advanced > Recreate Site Cache. Or if you don't really need site cache, go to 'Site settings' and disable the cache completely.

[tags]dreamweaver, adobe, software[/tags]