I was having many problems withdrawing btc and fiat from bitstamp.  I repeatedly entered the amount of bitcoin or fiat that I wanted withdrawn.  This went on for around 10 days with sporadic responses from my daily customer support tickets.  I always confirmed the withdrawal by clicking on the link within the confirming email, and did it right after I received the email. The request always showed "canceled" after one hour.  Finally, someone from bitstamp support suggested that I use the same browser when making the withdrawal through the bitstamp website and when I click the link within my confirming email.  The email address I use is my work email which is on the cloud.  I get on the internet outside of the cloud.  I went on the bitstamp website within the cloud, made the withdrawal request, went to my email within the cloud and clicked the link within the confirming email and I now see that the withdrawal is being processed.  When I withdrew btc in the past I did not have to do this, but apparently you do now.  So try staying within the same browser when confirming your withdrawal. 

I have not received the funds yet.  If I don't I will update.  Good luck