Redmine

need help-
I m trying to migrate from bugzilla(3.2.5) to redmine 1.2.1 with gemlist->

LOCAL GEMS ***
rack (1.1.1)
rails (2.3.14, 2.3.11, 2.0.2)
rake (0.9.2, 0.8.7)
rubygems-update (1.8.10)

i tried to run the script rake redmine:migrate_from_bugzilla RAILS_ENV="test" --trace
its output
root@svr tasks]# rake redmine:migrate_from_bugzilla RAILS_ENV="test" --trace
(in /opt/redmine)
rake/rdoctask is deprecated. Use rdoc/task instead (in RDoc 2.4.2+)
WARNING: Global access to Rake DSL methods is deprecated. Please include
... Rake::DSL into classes and modules which use the Rake DSL methods.
WARNING: DSL method Module#namespace called at /opt/redmine/lib/tasks/migrate_fr
WARNING: DSL method Module#task called at /opt/redmine/lib/tasks/migrate_from_bu
Invoke redmine:migrate_from_bugzilla (first_time)
Invoke environment (first_time)
Execute environment
Execute redmine:migrate_from_bugzilla
WARNING: Your Redmine data could be corrupted during this process.
Are you sure you want to continue ? [y/N] y

Please enter settings for your Bugzilla database
Migrating profiles...
Migrating products....
Migrating Issues.....\
****First time it ran fine, but took lot of time & had to hang it after 8 hrs when it was here.

it did showed things properly but custom fields were not coming & had some numbering issue. so i thought to restart it.
but is started with same cmd- it gave error>
Migrating productsrake aborted!
Validation failed: Identifier has already been taken
/usr/local/lib/ruby/gems/1.8/gems/activerecord-2.3.11/lib/active_record/validations.rb:1102:in `save_without_dirty!'
/usr/local/lib/ruby/gems/1.8/gems/activerecord-2.3.11/lib/active_record/dirty.rb:87:in `save_without_transactions!'
/usr/local/lib/ruby/gems/1.8/gems/activerecord-2.3.11/lib/active_record/transactions.rb:200:in `save!'
/usr/local/lib/ruby/gems/1.8/gems/activerecord-2.3.11/lib/active_record/connection_adapters/abstract/database_statements.rb:136:in `transaction'
/usr/local/lib/ruby/gems/1.8/gems/activerecord-2.3.11/lib/active_record/transactions.rb:182:in `transaction'
/usr/local/lib/ruby/gems/1.8/gems/activerecord-2.3.11/lib/active_record/transactions.rb:200:in `save!'
/usr/local/lib/ruby/gems/1.8/gems/activerecord-2.3.11/lib/active_record/transactions.rb:208:in `rollback_active_record_state!'
/usr/local/lib/ruby/gems/1.8/gems/activerecord-2.3.11/lib/active_record/transactions.rb:200:in `save!'
/opt/redmine/lib/tasks/migrate_from_bugzilla.rake:311:in `migrate_products'
/usr/local/lib/ruby/gems/1.8/gems/activerecord-2.3.11/lib/active_record/batches.rb:26:in `find_each'
/usr/local/lib/ruby/gems/1.8/gems/activerecord-2.3.11/lib/active_record/batches.rb:26:in `each'
/usr/local/lib/ruby/gems/1.8/gems/activerecord-2.3.11/lib/active_record/batches.rb:26:in `find_each'
/usr/local/lib/ruby/gems/1.8/gems/activerecord-2.3.11/lib/active_record/batches.rb:66:in `find_in_batches'
/usr/local/lib/ruby/gems/1.8/gems/activerecord-2.3.11/lib/active_record/batches.rb:25:in `find_each'
/opt/redmine/lib/tasks/migrate_from_bugzilla.rake:306:in `migrate_products'
/opt/redmine/lib/tasks/migrate_from_bugzilla.rake:509
/usr/local/lib/ruby/gems/1.8/gems/rake-0.9.2/lib/rake/task.rb:205:in `call'
/usr/local/lib/ruby/gems/1.8/gems/rake-0.9.2/lib/rake/task.rb:205:in `execute'
/usr/local/lib/ruby/gems/1.8/gems/rake-0.9.2/lib/rake/task.rb:200:in `each'
/usr/local/lib/ruby/gems/1.8/gems/rake-0.9.2/lib/rake/task.rb:200:in `execute'
/usr/local/lib/ruby/gems/1.8/gems/rake-0.9.2/lib/rake/task.rb:158:in `invoke_with_call_chain'
/usr/local/lib/ruby/1.8/monitor.rb:242:in `synchronize'
/usr/local/lib/ruby/gems/1.8/gems/rake-0.9.2/lib/rake/task.rb:151:in `invoke_with_call_chain'
/usr/local/lib/ruby/gems/1.8/gems/rake-0.9.2/lib/rake/task.rb:144:in `invoke'
/usr/local/lib/ruby/gems/1.8/gems/rake-0.9.2/lib/rake/application.rb:112:in `invoke_task'
/usr/local/lib/ruby/gems/1.8/gems/rake-0.9.2/lib/rake/application.rb:90:in `top_level'
/usr/local/lib/ruby/gems/1.8/gems/rake-0.9.2/lib/rake/application.rb:90:in `each'
/usr/local/lib/ruby/gems/1.8/gems/rake-0.9.2/lib/rake/application.rb:90:in `top_level'
/usr/local/lib/ruby/gems/1.8/gems/rake-0.9.2/lib/rake/application.rb:129:in `standard_exception_handling'
/usr/local/lib/ruby/gems/1.8/gems/rake-0.9.2/lib/rake/application.rb:84:in `top_level'
/usr/local/lib/ruby/gems/1.8/gems/rake-0.9.2/lib/rake/application.rb:62:in `run'
/usr/local/lib/ruby/gems/1.8/gems/rake-0.9.2/lib/rake/application.rb:129:in `standard_exception_handling'
/usr/local/lib/ruby/gems/1.8/gems/rake-0.9.2/lib/rake/application.rb:59:in `run'
/usr/local/lib/ruby/gems/1.8/gems/rake-0.9.2/bin/rake:32
/usr/local/bin/rake:19:in `load'
/usr/local/bin/rake:19
Tasks: TOP => redmine:migrate_from_bugzilla

Unable to start the script, do u need to drop mysql table & reconstruct it?? or what i m doing wrong?
+ i m new to ruby, so what does this test run & production run has a difference? i am able to see the changes in redmine.

any help is appreciated.