I found some bug in 4.0.5 source distribution 
/ext/standard/image.c

In function php_handle_jpeg,
variable marker must be initialized before for loop
like following

      marker = FP_FGETC(socketd,fp,issock);
      for(;;) {
         ...
         marker = php_next_marker(socketd,fp,issock);
      }

I modified souce code and rebuit php modlue.
Then getImagesize work properly for all jpeg images.

  Park Hee-Sob.