I know, I tried to answer.
I don't know if this has been explained to you but if you post with a question in another persons thread and people answer you and your query the poor person that asked the original question will get an email everytime someone answers, its quite annoying when it turns out all the answers given are for someone else. If it was you that posted a question and got a load of emails about your query and then saw that all the answers were for someone else you wouldn't be too chuffed would you?
Also there is the chance that the original question asked by the person will be taken over by someone else and forgotten about. So the person that asked the original question gets no replies at all.
Everyone has done it from time to time its just not a very nice thing to do for the reasons given above.
Much better to start your own thread or even to look through the past threads using the search facility first.