JeanMM, if you are using any software that blocks cookies (web filters, privacy tooks and some firewalls offer this feature) then you need to configure them to allow spamgourmet.com cookies to be able to log in.
If you are getting a message "There was a problem with your login..." and you have confirmed that cookies are being allowed, then the problem is likely to be that you are using proxy software that changes your IP address frequently (like
Steganos Anonym) - SpamGourmet uses your IP address to keep track of your session so if it changes, you need to log in again (see
Using Spamgourmet with anonymizing proxies for more details). Try disabling any such software.