Replacing Distributor every Few Months.

Every few months my 1990 2wd 1.5 Honda Wagon violently cuts out when driving and I have to replace the distributor. It runs for a few months and problem repeats. I'm aware of the rotor button coming loose causing similar symptoms and I always secure it with my own screw and lock tight.
Please please tell me what could be destroying the distributors. I would love this care and would like to drive it for several more years.
Please please tell me what could be destroying the distributors. I would love this care and would like to drive it for several more years.
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For more info:
http://www.civicwagon.com/showthread.php?74-SiWagon-Freebie-Honda-Ignition-Upgrade-D&highlight=ignitor