Freezing rails applications

Hi,      I have installed RAILS 2.0 in my machine. When I was freezing my rails application for rails 1.2.3. it is giving me the following error.

(in D:/ruby/reference_code/ublic_database/ublic_database/ ublip_project) rake aborted! no such file to load -- rcov/rcovtask D:/ruby/reference_code/ublic_database/ublic_database/ublip_project/ rakefile:10 (See full trace by running task with --trace)

please help.

Pavan