[Plugin: IntenseDebate Comments] Stuck on "Import in progress…" at 0%

I have a client who installed the IntenseDebate 2.9 plugin. When she went to import her old comments the importer gets stuck on a message that says “Import in progress…” at 0%. We’ve tried clicking “do a clean import” but that doesn’t do anything.

I read elsewhere that the plugin sometimes has problems when you also have the Maintenance Mode plugin installed, but she does not.

Any help would be appreciated. Thanks!