2.6 runs fine on 68K... I've had a similar problem that was caused by either having the thread manager enabled or not (I don't recall). But maybe we should back up here and verify that you've edited the config file properly...? If you've edited it with simple text it can cause problems... I always use bbedit.

FWIW my experience has been that Net Presenz is a bit less stable than a properly tweaked MacHTTP, but has the advantage of including FTP... and Gopher!!!