Errors if attempt to print invoice as pdf and delete team members

Hey,

thanks a lot for this great module! :)
I installed Storm and played around to get more involved in how it works and get always the following two errors...

1.) If I try to delete a 'Team member' I get this error:

warning: call_user_func_array() [function.call-user-func-array]: First argument is expected to be a valid callback, 'stormteammember_delete' was given in C:\xampp\htdocs\mysite.com\includes\form.inc on line 366.

If I navigate to an other page, this team member still exists, so it's not just an error but this function seems to not work for me.

2.) If I am in Storm > Invoices and want to print the current invoice as pdf I get the white screen with this error:

Fatal error: require_once() [function.require]: Failed opening required 'sites/all/modules/storm/libs/tcpdf/config/lang/eng.php' (include_path='.;C:\xampp\php\pear\') in C:\xampp\htdocs\mysite.com\sites\all\modules\storm\storminvoice\storminvoice.theme.inc on line 323

I'm using Drupal 6.9.

Please let me know if I'm missing something or do something wrong.
Would be great, if this errors could be fixed - I'd like to use this module for my current project.

Thanks in advance for your help.

Regards,
Stefan