After having seen this happen a few times, I felt the need to point out one fact about IRC; not everyone talks all the time. For example, I'm logged in almost 24/7, but obviously don't talk while I'm sleeping, or if I'm out doing other things. Many others stay logged in all the time, while some will connect in the morning and chat as time permits throughout the day, disconnecting if they're going somewhere or going to bed.
Why do I say this? Because this happens too often (name changed to protect the guilty):
23:29:40 < inaki> nao
23:29:40 < inaki> :!!!
23:32:13 -!- Someone [somehost] has joined
23:32:22 < Someone> Hello, anyone here?
23:32:38 < Someone> Bah.
23:32:43 -!- Someone [somehost] has left []
23:33:01 < Navi> Wow
23:33:22 < Navi> 21 seconds that time
It's not that nobody wanted to answer, but it's hard to answer someone who is only in channel for 30s when maybe you moved to another window to read email or check a website. So if you want to chat, definitely stop by - but stick around for at least a little while if you expect an answer :>