I don't see any reason why the title should be a question. What it should be is a summary or a lead-in to the body, so that when members are scanning down a list of questions, they can quickly tell what posts they might like to either try to answer or read for help with their problem. I think that question-form titles are in fact usually unhelpful -- there's no need for "How to" at the beginning of each and every title in the SO database.
Here's a few examples of original and edited titles. The new ones are succinct and deliver information without needing to have an interrogative word and a question mark, which would really just be noise. (Obviously some of these had other problems besides just being question-form.)
Then: how can we show Tab Widget on each and every Activity ? Event hat Activity is subActivity of FirstActivity.java
Now: Show Tab Widget on each and every Activity
Then: how to increase the width of a sprite through an animation??
Now: Increase the width of a sprite through an animation
Then: How to convert View to bitmap in android
Now: Convert view to bitmap on Android
Then: how to make a service in android which implements broadcast reciever?
Now: Make a service in android on Android which implements broadcast reciever
Then: hi frds, could you plz help me how to remove html tags from parsing data in blackberry application
Now: Remove HTML tags data in Blackberry application
Then: How to upload a picture/ friends list for an event using the Facebook Graph API in iphone ?
Now: Upload a picture/friends list for an event using the Facebook Graph API
I think that last one is the best example; the title is already quite long, and the "How to" adds nothing of value.