script/server error on Mac OS X

Hello all,

Recently, my apps stopped functionning properly on my dev machine
running Mac OS 10.4.11

Both script/server and script/console commands return this :

dub-macbook:~/Sites/contacts dub$ script/server
dyld: NSLinkModule() error
dyld: Symbol not found: _rb_thread_alive_p
  Referenced from: /Users/dub/.gem/ruby/1.8/gems/fastthread-1.0.5/lib/
fastthread.bundle
  Expected in: flat namespace

Trace/BPT trap
dub-macbook:~/Sites/contacts dub$ script/server
dyld: NSLinkModule() error
dyld: Symbol not found: _rb_thread_alive_p
  Referenced from: /Users/dub/.gem/ruby/1.8/gems/fastthread-1.0.5/lib/
fastthread.bundle
  Expected in: flat namespace

Trace/BPT trap

the same thing has happened to me.
Anyone know a solution?

For some reason, I tried uninstalling fastthread 1.0.5 with the
command gem uninstall fastthread -v 1.0.5 as explained here :
http://railsforum.com/viewtopic.php?pid=91777
It didnt work for me, for some reason fastthread 1.0.5 was still
listed as installed while performing gem -list
Bu then I removed all fastthread versions by hand with rm -dr
fastthread* in the proper directory, then reinstalled fastthread
1.0.4.
script/server was still broken, but script/server webrick worked
(after hitting ctrl-c, strangely).

I'm aware this is just a dirty workaround, not sure everything is in
proper working order.
I think I'll just install passenger and forget about mongrel, unless
anyone comes with a clean solution?

Same problem here, fastthread 1.0.4 are 1.0.5 are broken or otherwise
incompatible
with the latest update -
SOLUTION: uninstall fastthread 1.0.4 and explicitly install fastthread
1.0.1

here is partial log of my session

Hoover-iMac:/var/www/cook amateur_peasant$ mongrel_rails start -d
dyld: NSLinkModule() error
dyld: Symbol not found: _rb_thread_alive_p
  Referenced from:
/usr/local/lib/ruby/gems/1.8/gems/fastthread-1.0.4/lib/fastthread.bundle
  Expected in: flat namespace

Trace/BPT trap

Hoover-iMac:/usr/local amateur_peasant$ sudo gem uninstall fastthread
Password:

You have requested to uninstall the gem:
        fastthread-1.0.4
mongrel-1.1.5 depends on [fastthread (>= 1.0.1)]
If you remove this gems, one or more dependencies will not be met.
Continue with Uninstall? [Yn] y
Successfully uninstalled fastthread-1.0.4
Hoover-iMac:/usr/local amateur_peasant$ sudo gem install fastthread -v
1.0.1

THEN I CAN START mongrel

Hoover-iMac:/var/www/cook amateur_peasant$ mongrel_rails start -d
Hoover-iMac:/var/www/cook amateur_peasant$

versions:

Mac OS X 10.4.11
ruby 1.8.6 (2007-03-13 patchlevel 0) [i686-darwin8.11.1]
gem 1.3.1
rake 0.8.4
mysql-5.1.32