I don't know if you use the PHP wrapper provided by MailChimp, but when I look at their function:

function listSubscribe($id, $email_address, $merge_vars=NULL, $email_type='html', $double_optin=true, $update_existing=false, $replace_interests=true, $send_welcome=false)

$merge_vars contains: array GROUPINGS = Set Interest Groups by Grouping. Each element in this array should be an array containing the "groups" parameter which contains a comma delimited list of Interest Groups to add.

There goes maybe something wrong when calling this function (only the last group is added). And it can be the solution of my other bug ( it has to be a comma delimited list, so when you not escape a comma in the name of the interest group, it will treat the group as two groups).

Hey,
I'll test it tomorrow morning and will let you know.
Daniel

Ok, problem confirmed & fixed!
The fix will be in the next release(due either today or next week). If you cannot wait for it I can tell you which files to modify.
cheers,
Daniel

Ok, thanks for the quick fix! Is my other bug (https://compojoom.com/forum/bugs/17409-error-subscribing-to-interest-group-with-or )also solved with the fix?

I can wait till next week: I'm testing all the components before I will migrate my site (+ need to rewrite a custom component), so no hurry at all

The new release is out. It should fix the problems.
Cheers,
Daniel

Thank you very much You guys deserve more than 5 stars on JED