With collisions, Kirk means files that would end-up with the same name after your rename. Do you absolutely need your files to be named exactly as you describe? With some minor tweaking of the rename pattern, you can achieve lots. For instance, how about "{year4}-{month0}-{day0}-{hour24}-{minute}-{second}-" (yes, have the last dash). Then change the preference of the conflict renaming (edit|preferences|files) to (always) append a digit. This will give you
2007-09-22-01-42-56-.JPG, 2007-09-22-01-42-56-01.JPG, 2007-09-22-01-42-56-02.JPG, ...
or (if you chose to always append):
2007-09-22-01-42-56-01.JPG, 2007-09-22-01-42-56-02.JPG, 2007-09-22-01-42-56-03.JPG, ...
Hope this helps.