As bitcoin is becoming successful day by day ,
The number of people using bitcoin is increasing tremendously
This is leading to the sites having a lot of load.
So many transactions together crash the site.
But I can assure you that all the transactions will once be confirmed.
I use bitcoin on a regular bases.
I just pay more fees for transactions to take place quickly.
I do not think that paying more than the fee will speed up unconfirmed transactions. may now occur some problems in blockchain thus causing a delay confirmation. Well, it might be a natural thing, because at this time, bitcoin enthusiasts really multiply.