Installation error - mysqli

Uploaded and installed Omeka. I get the following error when I try to access the install.

"The Mysqli extension is required for this adapter but the extension is not loaded."

My web host says mysqli is enabled and they're not sure what's causing the error. Any suggestions?

The .htaccess files are present and Omeka is installed in my account's www directory.

And it turned out that my webhost only *thought* they'd enabled the mysqli extension. When I actually checked with phpinfo, I was able to confirm that it wasn't there. They rebuilt and now I can get to the install page, but I don't get any results back after I enter my info and press continue. Any idea what could be causing this next problem?

Are you still experiencing this problem? What happens you try to save the install page.. can you check to see if any data is saved to the database? Is there an error message displayed, or only a white screen?