LAMP warning on 3400mp

hi. i recently bought a new(authentic Osram) lamp for my dell 3400mp projector because the previous lamp simply stopped working one day.
i thought i'd blown it by not letting the projector cool properly.
Having replaced the old with the new( on comparison they are both exactly the same i.e. no burn out marks or evidence of cracking) the lamp light has come back on and i have no picture.  Ive since swapped them back to no avail.
A few forums have suggested this is a common problem but offer no solution.   i've been very careful not to touch the globe or damage any parts..
What else can be done? please help.Cheers in advance!