ssl 'certificate invalid' error

[harry archer]

My site is hosted on a shared ssl server and has worked fine for many years. A sudden problem with the PC running Actinic Catalog v7 has resulted in the error message 'the certificate authority is invalid or incorrect' when I try to connect to the server. My ISP has verified the certificate is OK and no changes have been made to the network setup. I don't know why the PC refuses to accept the server certificate, but is there a way to get Actinic to ignore this and connect anyway? I need a workaround so that I can connect and download orders.
Any suggestions gratefully received.
Regards Harry.

[Duncan Rounding]

Have you run a network test and checked for errors?
Can you ftp manually to hte server?

[harry archer]

Thanks for your response drounding - yes I did run a network check and got a 'certifcate invalid' error message.
However, the problem was with Microsoft. Our PC running Actinic has Windows XP operating system. It is set to Automatic Updates, but I have found out from Microsoft that XP updates no longer include Root Certificate updates. Once I manually installed the last Root Certificate update the problem disappeared.
Anyone running Actinic on a ssl server from a PC with Windows XP is likely to get this problem at some stage unless they manually install Root Certifcate updates (issued about every three months).