fatal error & sql qurey warning errors

I am using drupal 5.5, with all modules updated. The following error message was displayed when I was trying to access user page, for instance, http://site/drupal/users/whoever (with pathauto enabled)
Fatal error: Call to undefined function dprint_r() in /home/username/where/drupal_5_5/sites/all/modules/user_tags/user_tags.module on line 167

After commenting line 167 drpint_r($tags);
I received the following warning messages:

* user warning: Unknown column 'tu.rid' in 'field list' query: SELECT tu.rid rid ,t.* FROM term_data t INNER JOIN term_user tu WHERE tu.tid = t.tid AND tu.uid =6 in /home/user/where/drupal_5_5/includes/database.mysql.inc on line 172.
* user warning: Unknown column 'tu.rid' in 'field list' query: SELECT tu.rid rid ,t.* FROM term_data t INNER JOIN term_user tu WHERE tu.tid = t.tid AND tu.uid =6 in /home/user/where/drupal_5_5/includes/database.mysql.inc on line 172.
* user warning: Unknown column 'tu.rid' in 'field list' query: SELECT tu.rid rid ,t.* FROM term_data t INNER JOIN term_user tu WHERE tu.tid = t.tid AND tu.uid =6 in /home/user/where/drupal_5_5/includes/database.mysql.inc on line 172.
* user warning: Unknown column 'tu.rid' in 'field list' query: SELECT tu.rid rid ,t.* FROM term_data t INNER JOIN term_user tu WHERE tu.tid = t.tid AND tu.uid =6 in /home/user/where/drupal_5_5/includes/database.mysql.inc on line 172.

The problem happened when you upgraded from 5.x-1.x, where 5.x-1.x create a table with 3 fields (vid, tid, uid), and 5.x-2.x uses rid, tid, uid.

So to solve the problem, simply change field vid to rid, you can execute
alter table term_user change column vid rid int(10) unsigned; <- in mysql prompt
or make according changes in user_tags.module.

Problem solved.