2 most likely causes are:
1) Excessive heat due to poor heat conductivity--low air flow, no heat transfer paste,etc
2) Low system voltage--leading to excessive current draw and excessive heat generation in the EZL
3) Loose/poor ground connections causing voltage spikes

Why do you have to use 'european' EZL--the american one will have less timing advance,lower RPM limit?. Won't it work just fine?