OTF ligature limit?

Hi,

I was wondering if anyone could help me out with ligatures? I've created an OTF font where I've added a large number of ligature substitutions and they seem to work without issues until the number of words to be substituted exceed 2400-2500. I'm using FontLab to execute the ligature scripts.

Currently the font has 1 482, which shouldn't be the reason for the ligature substitutions to fail I guess. Any help would be appreciated.

My goal is to understand the limits for ligatures and a possibility to overcome them.

Thank You,