Low Voltage dimmer problems

[aaargh]

Hi - have had a low voltage light for about 3 years - looks a bit like this one:
http://www.argos.co.uk/static/Product/partNumber/0021993/Trail/searchtext>LIGHT.htm

recently, have decorated the dining rooms and fitted this light back, with a dimmer from screwfix:
http://www.screwfix.com/search.do;j...CSTHZOCFFI?_dyncharset=UTF-8&fh_search=96836.

So the light has 5 x 20w 12v G4 and the dimmer is 500W suitable for low and mains volts.

Trouble is though when you switch the light on it pulses at about 1/2 brightness.

Any ideas what the problem is? - dimmer works fine with a standard bulb. Have I got the wrong dimmer or is the light fitting not dimmable?.
Can you get non halogen g4 bulbs and would it make any difference?

Thanks in advance

 

[breezer]

probably not suitable for dimming, not all lights are. Look at the transformer in the light, does it say suitable for dimming?

 

[333rocky333]

Looks like it may have a wire wound transformer inside the head.

Usually an inductive dimmer suitable for wire wound transformers will dim these.

Usualy 500w or 630w rated