Check all of your wires with an Ohm meter (resistance). Also check their physical integrity. Check for corrosion and what not at both ends. Some di-electric grease at the connections wouldn't hurt either. Also make sure they're spaced out properly. If they're resting against each other that can cause misfiring problems as well.
Check your plus. Make sure the element is intact, gapping is propper, no scorching or any other common problems with plugs.
Check your coil-packs for corrosion. Again, di-electric grease is a good thing.
Start your car in the dark. Look for any sparks. You shouldn't see ANY. If you do then something is exposed and its arcing. Take it to your mechanic.
: Try and find out what they did to "fix it" as rob said. That might offer some insight into your problems. Good luck and keep us updated.
[Edited by mouse on Dec 2, 2002 6:22 PM]