Multiple image uploads not handled properly in path replacements

I am still learning Drupal, so this may very well be due to user-error here ... :)

Situation: custom content type with a Imagefield added to it. When uploading multiple images (in this case, two images), the destination filenames seem to get munged a bit. I uploaded "studio1.gif" and "studio2.gif". The filenames saved were studio_1.gif and studio_1_0.gif. The content itself is fine, but that second filename gets hosed. Again, I could be missing something. My settings below:

Imagepath settings for this content type:

Field name: field_images
Field Type: File
Widget Type: Image

File-Path: faq-images
File Path Replacement: [field_images-filefield-filename]
Cleanup using Pathauto: No
Covert to lower case: No
Transliterate: No

Running:
Drupal 6.13
CCK 6.x.2-4
ImageField 6.x.31
Image Resize Filter 6.x-1.4

Any ideas?