Thanks, opening the forum in chrome and following your instructions I was able to see the broken padlock.
Unfortunately this seems to be a bug in chrome.
Here is the bug report that has been going on for 2 and a half years now.
http://code.google.com/p/chromium/issue ... l?id=24152
The beds24 booking page is secure and all other browsers report it as secure, it's just chrome has this weird bug that hopefully one day will be fixed.
This warning has nothing particular to do with Beds24.
Even if I go to the secure google page in chome after viewing this forum page, I get the ssl warning and broken padlock.
https://www.google.com