Glastonbury festival fans experiencing problems purchasing tickets have been assured they are being investigated.
Festival founder Michael Eavis said ticket sales "went like a dream"
A number of customers who successfully bought tickets to the event were later told their order had been cancelled due to problems "obtaining payment".
Agency SeeTickets has said that each case is being looked into, and has promised to "iron them all out".
All 112,000 tickets to the June event were sold out in two hours on Sunday.
The glitch was reported by a number of would-be festival-goers who wrote into the BBC News website on Monday.
One hopeful's ticket was successfully booked, but he was later informed it had been cancelled due to payment difficulties.
His ticket was eventually secured, but he felt it was "unforgiveable" that there was no specific reference to the problem on the Glastonbury, SeeTickets and Aloud websites.
Sir Paul McCartney was among the festival performers last year
SeeTickets, which handles the technical side of Aloud.com - Glastonbury's online retailer - admitted there had been some problems.
"It is possible that this is a mistake which lies more with the credit card companies," SeeTickets managing director Nick Blackburn told Music Week magazine.
"Until we check the queries on an customer by customer basis, we won't know the facts," he added.
They have urged those who have encountered the problem to call the Glastonbury customer service helpline.
A Glastonbury spokesman said there is an inquiry desk dedicated to dealing with specific ticketing issues, and the information is displayed on the festival's website.
Most fans still hailed the revamped system an improvement on last year, when festival devotees spent all night trying to get through on phone lines that jammed and a website which crashed.