FGC 2339 and IC 5249, both low-mass galaxies, could not be fit with the Two Disk models, while the Single Disk fit gave very high 
values, showing the existence of a vertical structure at higher scaleheight that is clearly distinct from a single thin disk. This vertical structure however, cannot be described as a superposition of a thin plus a thick disk. A study of the shape on contour maps and the radial surface brightness profiles (see Appendix A) shows both galaxies to possess a extended box shaped structure. This is especially strong in IC 5249 which shows a long radial range in which the surface brightness hardly decreases. Also in the contour map the isophotes remain very parallel to the major axis. What these flat vertical structures are we cannot say. It could be a long bar or (multiple) inner rings within the galaxy, which affects the vertical structure along the whole 
-region. We show here that they are not thick disks in the traditional sense; as a superposition of a thin and a thick disk is not a valid description of the vertical structures we see. This in contrast to the easy fits on our other sample galaxies.
A reassessment of the vertical structures in (low-mass) late-type galaxies might be necessary. The question is that we don't know if what we see is something like a thick disk or a completely different structure. Our findings resemble the findings of Matthews matthews2000, who suggests that the superthin edge-on Sd galaxy UGC 7321 has multiple disk subcomponents with different scaleheights, comprised of stellar populations with different ages and velocity dispersions. FGC 2339 and IC 5249 could be similar galaxies to UGC 7321.
The issue could also be that low-mass galaxies have not developed a thin with thick disk structure and can not be used to determine a distinct thick disk component. A thick disk might require more mass and potential energy to develop a thick disk component. All in all this will have its implications on the hypotheses on the formation and evolution of galaxies.