No help? :(
Maybe you could show us the import mapping or the structure of your spreadsheet.
There isnt much to go on in your post.
The portal on the Groups layout is simply displaying the Full Name and Email fields from the related Contact record.
I'm guessing when you imported, you unchecked the box for "perform auto-entry options," with the result your Contacts have no ID. The ID field is used to link the Contacts and Groups.
!!!!! STOP !!!!! BACK UP YOUR FILE FIRST !!!!!!
Go to any Contact layout, go to layout mode, and put the "k_ID_Contact" field on the layout.
Do a Find in this field for = (i.e. blank).
Did you find some records?
If so, go to Define Database and in the Options for k_ID_Contact, uncheck the checkbox that says "Prohibit modification..." Click OK.
Once you've done that, click in the field, and then under Records (or Contacts -- this template uses custom menus), choose Replace field contents... Choose the serial numbers option. Note that by default it shows the next unused serial number, and the "update" checkbox is selected. Click Replace.
Awesome. Got it, thanks!