When signing up, there appears to be one of those verification systems to stop auto-joining (by what, robots?) However, the codeword or box does not appear. This is in a range of browsers on a Mac. We have signed up on a Mac before though.!](https://sslproxy.getsatisfaction.com/sslproxy/SWhAdDNLMG5zdGFuVGlWenmLbJDGd3CABhjZermgcystANA4T6nd0pzV0fSzBRRGOd17A4b8ZLwi6-HESbXI0ip521nqFlqovTutPSH1n03h28W4VVJ_OppSnU8EDG3tgNdfyyBZeiO1ioubFgHbNeDgG_BirxlSfzXaKSaErwU=.png)](http://s3.amazonaws.com/satisfaction-production/s3_images/456975/Screen_shot_2011-04-04_at_10.18.11.png)
please have a look at http://community.prezi.com/prezi/topi… and follow the advice there.