Unreadable error using FCGI

I recently installed mod_fcgi on to Amazon EC2 64bit Linux AMI and using Movable Type 5.13 with it. Here is my error log.

[warn]mod_fcgid: error reading data, FastCGI server closed connection, referer: http://xxx/mt.fcgi?__mode=start_rebuild&old_previous=1&is_new=0&next=0&old_status=2&type=entry-1&blog_id=1&entry_id=1

[error]Premature end of script headers: mt.fcgi, referer: http://xxx/mt.fcgi?__mode=start_rebuild&old_previous=1&is_new=0&next=0&old_status=2&type=entry-1&blog_id=1&entry_id=1

My .conf file for /etc/httpd/conf.d/fcgid.conf

LoadModule fcgid_module modules/mod_fcgid.so

# Use FastCGI to process .fcg .fcgi & .fpl scripts
AddHandler fcgid-script fcg fcgi fpl .cgi

# Sane place to put sockets and shared memory file
FcgidIPCDir /var/run/mod_fcgid
FcgidProcessTableFile /var/run/mod_fcgid/fcgid_shm

<IfModule mod_fcgid.c>
  AddHandler fcgid-script .fcgi
  SocketPath /tmp/fcgid_sock/
  FcgidConnectTimeout 1000
  FcgidMaxProcesses 1000
  FcgidMaxProcessesPerClass 100
  FcgidTerminationScore 20
  FcgidSpawnScore 180
  FcgidIdleTimeout 1000
  FcgidIOTimeout 1000
  FcgidMaxRequestLen 100485760
</IfModule>

Movable Type rebuilds the html but right after about 4~5minutes it gives me "Internal Server Error". I thought it was an timeout error so I just cranked up all the timeout related settings but same result.

UPDATE:

Further research tells me using Apache 2.2.x VirtualHost setting has some bug that prevents fcgi conf file to resets to default setting. So I set the FcigdConnectTimeout etc, within the VirtualHost, but result has not changed.