Data Encryption Error. What causes it?

[tomld2]

I sometimes get customers who say when they try to access my secure order page (https://) they get "Security failure. Date decryption error". What causes this and how can I fix it? I have a GeoTrust web certificate and I 'assume' it works for about 99% of my customers, as the complaints about this error are not too frequent. Any ideas?

Thanks
Tom

[marcs]

GeoTrust certs are not recognized as issued by a trusted source for some (slighty) older browsers.

Check what browsers (+ version) those people are using and maybe that will give you more to work with.