I would also check database user name and password and make sure not only it's correct but also make sure the user has proper write/access privileges as well.
It's likely that the test server setting and the remote server setting has to match for some reason. In my case, I didn't have the actual remote server (hosting account) so I simply used "local" option and matched them that way. Because of URL Parameter troubles I ran into, I suspect it might cause some issues if you have to use something like "http://localhost/~site" for testing server while having a real domain name for remote server. PowerCMS seems to be very picky about these settings. In my case I run my local test sites on MAMP Pro with "real" domain names. MAMP Pro lets me set up domain names locally very easily, so I can fake a real hosting including domain names. Or, I would just wait to run the installer until I upload the whole package to a remote hosting and run the installer script there.
WA, for your sake I really hope you guys will be able to address all these things at the extension level so we won't have to figure things out like we have been having to. This should've been caught in QA process. So many people are having trouble here....