[TYPO3] I hit the limit Flash Slideshow extension can show?

[Bing Du]

Hi,

Typo3 V4.0.4
Flash Slideshow (slideshow) 0.2.2

I've selected 50 JPG files I want to be included in the flash slideshow. 
When I selected the 51 JPG, a yellow ! mark showed up next to the
selection box.  Then when I saved the slideshow with 51 JPG selected, I
got this message:

The fields marked with a yellow exclamation mark are not yet correctly
filled in.  Please complete them properly.

I checked the slideshow configurations in the TS constant editor but
didn't see there is any limit setting that can be changed.  Anybody using
the Flash Slideshow know where the limit is set?

Thanks in advance,

Bing