Interior LED bulbs problem with Lancer

[melonvitara]

hey guys,
i recently helped my frd bought some LED bulbs for his Lancer
they are 31mm festoon bulbs (the one we used for the domelight)
he uses 2 of them for the maplight
these ones
http://cgi.ebay.ca/1pc-31mm-3022-3175-6-SMD-LED-White-Festoon-Bulb_W0QQitemZ190202996547QQihZ009QQcategoryZ33713QQtcZphotoQQcmdZViewItem

now the problem is when he turns both of them on when the engine is off, they light up for a while then become really dim and flicker slightly
but when the engine is on, they light up fine even for a long period of time
if he turns on one only, sometimes it lights up fine for a while and become dim and flicker again
or
upon turning that one on, it would be dim and flicker

we tried it on my car last night it worked flawlessly
so anybody know what's wrong?

[SamSamSam]

no idea..my pocket door led, bought from parker was working fine for 2 months..now the right hand side..it flickering like shit..and sometimes doesn't for a good 10sec..then flicker again. Maybe its because i slam the door too much o.O?

[Overseas Auto1]

I think thats because LED want to have a required voltage