What are you using to ballast the new bulb? I'd be very hesitant to go up
in
wattage, in that unlikely scenario that it catches fire, you're pretty
well
screwed.

I'm not sure what you mean, but both are video projector bulbs- they use
25KV to start an arc, then about 20-50 volts to maintain the arc. So of
course I am using the original ballast (100 watt) with the slightly higher
(120 watt) bulb. The ballast is specifically designed to limit current, or
you could say regulate current, so I am pretty sure it is only putting out
100 watts, although it might be generating a slightly different voltage to
do so, which is really a function of the electrode gap. Thus it might be
getting a little hotter, hence the extra fans. This LCD projection tv had
30,000 hours on it when I got it for $1.25, but it really does look great. I
have no worry about it catching fire, but there could be a component failure
in it's future.

On the other hand, putting a lower watt bulb than the ballast is designed to
use will result in a very hot bulb explosion rather quickly, as the ballast
IS going to put out the same wattage regardless of which bulb is in place.

Normally, the problem of switching bulbs is that the ballast will not start
the arc at all. But I got lucky and it starts on the first attempt every
time.