Does this error comes from the driver in my release
http://acs-misc.sourceforge.net/ns_rel_beta2.html? If not, then I can't help you much. If yes, I've compiled the latest version. Maybe I screwed up something (like not compiling it with FOR_ACS or something) I haven't tested it that much.
But then again, it looks like you're using OpenACS 4. In short: post more information, where did you get the driver, which version of AOLServer are you using, which OpenACS, are there any other things in the server log that look relevant?