Marc,
O.k., but did you try it? If you'll notice in nph-build.cgi, whenever the Links or Categories tables are called with $DB->table('Links'), or $DB->table('Category') they don't use the prefix. I think the prefix is already specified from the setup. Anyway, when I first set this up on my nph-build.cgi I had the same problem as you are describing, until I removed the prefix. But as you mentioned, maybe your server is set up differently, or there is a problem with the version of MySQL.
-FrankM
O.k., but did you try it? If you'll notice in nph-build.cgi, whenever the Links or Categories tables are called with $DB->table('Links'), or $DB->table('Category') they don't use the prefix. I think the prefix is already specified from the setup. Anyway, when I first set this up on my nph-build.cgi I had the same problem as you are describing, until I removed the prefix. But as you mentioned, maybe your server is set up differently, or there is a problem with the version of MySQL.
-FrankM