XmList Widget Max Item Length

I have an XmList Widget which contains (XmString) items that are roughly 2k in length. I need to add items which can be over 25k in length. When I get past roughly 3.5k, the list widget collapses into a narrow strip attached to the left side of its parent.

Is there a size restriction on the length of an item that can be displayed in an XmList Widget?

This number seems to vary depending on the op system (or this may be a server limitation); Linux 4.1k and windows 3.6k.