installs wrong package version when a later version is available

I want drush to update the views module to 7.x-3.0-rc1. I have an older -dev version installed, and a more recent -dev version is available. Here's what happens:

$ drush up views-7.x-3.0-rc1
Update information last refreshed: Thu, 06/30/2011 - 05:42

Update status information on all installed and enabled Drupal projects:
 Name                           Installed version  Proposed version  Status                                   
 Advanced help                  7.x-1.0-beta1      7.x-1.0-beta1     Up to date                               
 Automatic Nodetitles           7.x-1.0            7.x-1.0           Up to date                               
 Drupal core                    7.4                7.4               Up to date                               
 Block Class                    7.x-1.x-dev        7.x-1.x-dev       Up to date                               
 Corresponding node references  7.x-4.x-dev        7.x-4.x-dev       Up to date                               
 Chaos tool suite               7.x-1.0-beta1      7.x-1.0-beta1     Up to date                               
 Date                           7.x-2.0-alpha3     7.x-2.0-alpha3    Up to date                               
 Devel                          7.x-1.x-dev        7.x-1.x-dev       Update available                         
 DHTML Menu                     7.x-1.0-beta1      7.x-1.0-beta1     Up to date                               
 IMCE                           7.x-1.4            7.x-1.4           Up to date                               
 IMCE Wysiwyg bridge            7.x-1.x-dev        7.x-1.x-dev       Up to date                               
 Name Field                     7.x-1.x-dev        7.x-1.x-dev       Up to date                               
 Name Database                  7.x-1.0-beta2      7.x-1.0-beta2     Up to date                               
 References                     7.x-2.x-dev        7.x-2.x-dev       Update available                         
 Node Connect                   7.x-1.x-dev        7.x-1.x-dev       Up to date                               
 Nodereference Count            7.x-1.x-dev        7.x-1.x-dev       Up to date                               
 Pathauto                       7.x-1.0-rc2        7.x-1.0-rc2       Up to date                               
 Token                          7.x-1.0-beta2      7.x-1.0-beta2     Up to date                               
 Views                          7.x-3.x-dev        7.x-3.x-dev       Specified version available              
 Wysiwyg                        7.x-2.x-dev        7.x-2.x-dev       Update available                         
 Zero Point                     7.x-1.1            7.x-1.1           Up to date                               


Code updates will be made to the following projects: Views [views-7.x-3.x-dev]

Note: A backup of your project will be stored to backups directory if it is not managed by a supported version control system.
Note: If you have made any modifications to any file that belongs to one of these projects, you will have to migrate those modifications after updating.
Do you really want to continue with the update process? (y/n): y
Project views was updated successfully. Installed version is now 7.x-3.x-dev.
No database updates required                                                                                                [success]
Finished performing updates.                                                                                                [ok]

Note that:

• I ask drush for version 7.x-3.0-rc1.
• Drush agrees that the specified version is available.
• Drush installs the later -dev version anyway.