Nothing is perfect off the shelf and your wiki will be no different. Most wiki packages are designed to be customized and extended, so take advantage of that by investing in a few days of developer time to modify it to suit your needs. Re-evaluate wiki usage at regular intervals to gather feedback on the most common gripes and dedicate resources to adjusting the wiki accordingly. The few hours or days spent tweaking it will come back tenfold in time saved by users.
Slashdot Mirror
See point #3 on the 10 Tips for a Successful Wiki poster from gdc;
Invest in your wiki
Nothing is perfect off the shelf and your wiki will be no different. Most wiki packages are designed to be customized and extended, so take advantage of that by investing in a few days of developer time to modify it to suit your needs. Re-evaluate wiki usage at regular intervals to gather feedback on the most common gripes and dedicate resources to adjusting the wiki accordingly. The few hours or days spent tweaking it will come back tenfold in time saved by users.