You can EITHER use Dave OR OS 10+ file sharing. If you have Dave installed, you can't use the OS native functions, because Dave preempts them. If Dave is so hosed up that you can't completely uninstall it, then you may have to reinstall your OS, or worse, reformat the drive and start over.
Isn't there an application installation log buried deep in the innards of OS X that tells you exactly which files were installed with which application? I can't remember exactly where this log would be found (the folder has a different name from the Linux equivalent, and Linux gives it a name that's different from BSD and any other flavor of Unix). Anyway, if you can find that log, you can manually remove all the Dave files, which should let you use the OS file sharing.