Thank you thoze,
I had the same problem as WildAl but after using "StartStreamMatchingAllConditionAsync" function as you suggested, I am now able to get the tweets, however the application is freezing and I can't click on any other button such as "Stop Stream".
I tried to use "DoEvents" method but to no avail.
Also I coudn't use the keyword "await" since it is not available in Visual Studio 2010 which I have.
Any other suggestions?
By the way I use VB.net code:
filteredStream = Stream.CreateFilteredStream()
AddHandler filteredStream.MatchingTweetReceived, AddressOf MatchedTweetReceivedEvent
Sub MatchedTweetReceivedEvent(sender As Object, e As Tweetinvi.Core.Events.EventArguments.MatchedTweetReceivedEventArgs)