[Gmod-ajax] trouble with GFF3 parsing

[James C. <ca...@gm...>]

I have the following file:
"""
##gff-version 3
##sequence-region CYP2C8 1 36725
CYP2C8	src	Feature	4100	4291	.	-	.	ID=37
CYP2C8	src	Feature	6125	6213	.	-	.	ID=38
CYP2C8	src	Feature	8093	8330	.	-	.	ID=39
CYP2C8	src	Feature	11013	11204	.	-	.	ID=40
CYP2C8	src	Feature	23538	23764	.	-	.	ID=41
CYP2C8	src	Feature	20003	20213	.	-	.	ID=42
CYP2C8	src	Feature	32411	32944	.	-	.	ID=43
CYP2C8	src	Feature	34400	35725	.	-	.	ID=44
"""

Running "flatfile-to-json.pl --gff /tmp/e.gff --tracklabel 'feature'
--cssclass feature --out browsers/human-gene-test --type Feature"
produces the following track:

"featureNCList":[[4099,4291,-1,"37"],[6124,6213,-1,"38"],[8092,8330,-1,"39"],[11012,11204,-1,"40"],[23537,23764,-1,"41"]]

You can see that everything above 30,000 bases is ignored.

Changing the sequence-region pragma to be a larger region fixes the problem:
##sequence-region CYP2C8 1 46725

What is going on here?  Why do I not get all the features I declared?

thanks,
James