Can you set/change the cut-off voltage for Lipo mode? It is probably set at 4.20V/cell as default for Lipo. If you can adjust it, change it to 3.60V/cell and it will charge your LiFe packs fine. They both use the same CC/CV charging method, only the cut-off voltage is different between the two types. If you do change it, don't forget to change it back to 4.20V/cell when charging Lipos again.
If you can't change it, you could charge it on Lipo mode, and watch until it gets to 3.60V/cell then just stop the process manually. I wouldn't really endorse this method because there is a risk of overcharging the cells, but it will work in a pinch.
Serpent 811Be - Jammin X2 Carbon e-GT conversion - Axial SCX10 Honcho