Thanks for your replies...
The module is a LM12 (UK) lamp module for wall outlet.
Code on sticker is 06E21
Bulbs used/failed are true incandescent (just basic filament bulbs)
No in-line dimmer - just a cable direct to light fitting with in-line on/off switch.
Looking forward to your comments....
Dave
According to Marmitek's web page:
http://www.marmitek.com/en/catalogus/product.php?subgroep=6&product=52the LM12 appears to be the 230V, 50Hz functional equivalent of the US model LM465 (original design) plug-in Lamp Module.
Marmitek's FAQ for the LM12 has this:
------------------------
Product: LM12 Lamp/Dimmer Module Art. nr. 08910
Question: The lamp starts to flicker and cannot be controlled anymore, unless I take the module out of the wall socket and then insert it again. What do I need to check?
Answer:
Check whether the load is high enough (min. 40W). Halogen lighting cannot also be connected to the module. Use a normal light bulb. If the problem persists, then the device may be faulty.
------------------------
I think they are mistaken about the minimum wattage - modules that have connections to both line and neutral don't require a minimum. (A 4 Watt night light I have currently plugged into a LM465 switches and dims normally.) I can therefore only conclude that you have a defective LM12.
It's possible the frequency of the flicker coincides with a mechanical resonant frequency of the filament in the bulb, causing the short life.