Since there's no shows for Scotland again this tour I decided to try for Paris.
Logged on at 10am and sure enough, timer on website just kept going round and round (had 4 separate pages open across 2 PC's) and it was like this for nearly 50 minutes.
Sometimes when I tried to open a new page I was getting the message that the code wasn't valid either!
Anyway, at about 10.50 I opened a new page and got straight through and with the option of tickets for anywhere in the venue and got 2 for GA!
So, keep trying!