And shouting and/or ranting about there being so many people and none helping you doesn't help your case because
a) Not everyone is online.
b) Of the people who are online, not everyone knows the answer.
c) Of the people who are online and know the answer, very few would reply if you have a bad attitude.
Thus going into an irc channel, your best bet is to say something like this:
"Hi. I had a question regarding <topic>"
"<insert question here>"
Now, as lizard.boy said, you should patiently wait. Maybe if you want, ask your question again in the same fashion in an hour or two so that the people who just came in or the ones who just came online can have a look at it.
Why do the members in the chan not browse up and read?
a) Most people ask questions and leave within 60-120 seconds (ie are impatient)
b) Some people are connected via bncs which basically means, you will see them as online even when they aren't and when they do come online, they usually don't keep logs of previous activity.
Thus to sum up,
ask your question kindly and wait patiently for an answer. Being impatient/rude never helps your case