Piston Update Problem

[Mark Dodwell]

I've got several plugins which I imported with piston into my rails
project. However, when I update them it seems to change them back to an
earleir revision (e.g. on rspec_on_rails it goes from r3320 back to
r3278 which has lots of changes) -- why does it do this? Any clues?

... piston update
Processing 'vendor/plugins/rspec_on_rails'...
Fetching remote repository's latest revision and UUID
Restoring remote repository to known state at r3320
Updating remote repository to r3278
Processing adds/deletes
Removing temporary files / folders
Updating Piston properties
Updated to r3278 (18 changes)
Processing 'vendor/plugins/rspec'...
Fetching remote repository's latest revision and UUID
Restoring remote repository to known state at r3320
Updating remote repository to r3278
Processing adds/deletes
Removing temporary files / folders
Updating Piston properties
Updated to r3278 (53 changes)

This is really got me, I can't find anything on this?

Thanks,

~ Mark