wp-nice-categories15.php problems

Anyone use this plugin?

I am trying to use it so WP doesn’t like my categories like

Cat1
Cat2
Cat3

And instead like Cat1 – Cat2 – Cat3

When I load the plugin I get the following errors:

Warning: Cannot modify header information – headers already sent by (output started at /homepages/39/d87590790/htdocs/nickhates.us/wp-content/plugins/wp-nice-categories15.php:32) in /homepages/39/d87590790/htdocs/nickhates.us/wp-admin/admin.php on line 10

Warning: Cannot modify header information – headers already sent by (output started at /homepages/39/d87590790/htdocs/nickhates.us/wp-content/plugins/wp-nice-categories15.php:32) in /homepages/39/d87590790/htdocs/nickhates.us/wp-admin/admin.php on line 11

Warning: Cannot modify header information – headers already sent by (output started at /homepages/39/d87590790/htdocs/nickhates.us/wp-content/plugins/wp-nice-categories15.php:32) in /homepages/39/d87590790/htdocs/nickhates.us/wp-admin/admin.php on line 12

Warning: Cannot modify header information – headers already sent by (output started at /homepages/39/d87590790/htdocs/nickhates.us/wp-content/plugins/wp-nice-categories15.php:32) in /homepages/39/d87590790/htdocs/nickhates.us/wp-admin/admin.php on line 13

It would appear the plugin does not work, (it is the 1.5 version)

Any suggestions to fix this or perhaps another way to list my categories this way?

Thanks