gem mongo is causing problems again

I am not sure why, but I think they made some mistakes when
generating the gemspec, causing RubyGems 1.3.7 under Ruby 1.9.2+
failed to parse the gemspec, ending up with undefined constant Sych::Sych.
(uninitialized constant Syck::Syck (NameError))

That means, I can't push to Heroku on 1.9.2 stacks, because they are
using a very old version of RubyGems, which is 1.3.7 and cannot handle this.
(It worked fine on my computer and I am using RubyGems 1.8.11)

Downgrading mongo gem from 1.5.0 to 1.4.0 would fix this.

*

The problem they made before was that they deleted 1.4.1 in the gem repository.
I've complained this on twitter that time. (a) (b)
As you can see in /gems/mongo/versions:

1.4.1 October 17, 2011 yanked

Heroku also did this before /gems/heroku/versions
According to the history, they did this 3 times. I think I run into this 1 or 2 times.
At first, I thought it's a RubyGems bug... then I realized that it's just got deleted.

:(