Hey Michael,
I have exactly the same problem with CPT – I named it with a space in the slug and now I can’t delete it. The problem is that the solution you suggested doesn’t work for me. Please tell me if we are talking about exporting database or exporting content from WP (via WP Dashboard) – and then changing the name of the CPT? Either Way I can’t locate the code to change the name of the slug.
Any help would be much appreciated.