I've recently installed Zimbra Desktop on my Macbook Pro running OSX 10.5.8. When I enter in all my details to connect to my regular Zimbra account it throws the following error;

zclient.IO_ERROR: RSA premaster secret error

I thought it might just be a problem with the Zimbra settings so I tried my gmail account and it gives this error;

service.FAILURE: system failure: caught security exception

I then tried set it up for two other users, it works for one but not for the other, it gives the same error as it gives me.

Does anyone have any ideas as to what can be causing it? It has really got me stumped. If you need more info just let me know and I'll get it