RJS can't modify frozen string

Any ideas why RJS would start causing "can't modify frozen string"
errors? This was working last night and I'm not sure what could have
been changed to cause this. The app is on a VPS not shared hosting.

/!\ FAILSAFE /!\ Fri Jun 20 20:13:37 -0700 2008
  Status: 500 Internal Server Error
  can't modify frozen string
    /usr/local/lib/ruby/gems/1.8/gems/actionpack-2.0.2/lib/
action_controller/request.rb:462:in `gsub!'
    /usr/local/lib/ruby/gems/1.8/gems/actionpack-2.0.2/lib/
action_controller/request.rb:462:in `clean_up_ajax_request_body!'
    /usr/local/lib/ruby/gems/1.8/gems/actionpack-2.0.2/lib/
action_controller/request.rb:380:in
`parse_formatted_request_parameters'
    /usr/local/lib/ruby/gems/1.8/gems/actionpack-2.0.2/lib/
action_controller/cgi_process.rb:78:in `request_parameters'
    /usr/local/lib/ruby/gems/1.8/gems/actionpack-2.0.2/lib/
action_controller/request.rb:287:in `parameters'
    /usr/local/lib/ruby/gems/1.8/gems/actionpack-2.0.2/lib/
action_controller/request.rb:22:in `request_method'
    /usr/local/lib/ruby/gems/1.8/gems/actionpack-2.0.2/lib/
action_controller/request.rb:35:in `method'
    /usr/local/lib/ruby/gems/1.8/gems/actionpack-2.0.2/lib/
action_controller/routing.rb:1483:in `extract_request_environment'
    /usr/local/lib/ruby/gems/1.8/gems/actionpack-2.0.2/lib/
action_controller/routing.rb:1424:in `recognize'
    /usr/local/lib/ruby/gems/1.8/gems/actionpack-2.0.2/lib/
action_controller/dispatcher.rb:170:in `handle_request'
    /usr/local/lib/ruby/gems/1.8/gems/actionpack-2.0.2/lib/
action_controller/dispatcher.rb:115:in `dispatch'
    /usr/local/lib/ruby/gems/1.8/gems/actionpack-2.0.2/lib/
action_controller/dispatcher.rb:126:in `dispatch_cgi'
    /usr/local/lib/ruby/gems/1.8/gems/actionpack-2.0.2/lib/
action_controller/dispatcher.rb:9:in `dispatch'
    dispatch.cgi:10

Very weird - it works in Firefox and Opera, but not Safari.

Has anyone seen this before?

Very weird - it works in Firefox and Opera, but not Safari.

Has anyone seen this before?

IIRC this only happens with fastcgi.

Fred

Is there any way around it, other than switching to Mongrel? I may
just resort to coding in jQuery myself.

Is there any way around it, other than switching to Mongrel? I may
just resort to coding in jQuery myself.

I don't think switching to jQuery will help - this processing is done based on the content type of what is submitted.

Fred

Same problem, same error in request.rb. Tested in Camino, too -
worked OK.

Any ideas for how to deal with this? I've got a large amount of code
that I would hate to have to rewrite.