I googled guar hydroxypropyltrimonium chloride and ended up at Tightly Curly. This is what she wrote about it:

Guar hydroxypropyltrimonium chloride
Caution
Conditioning ingredient. Good in products that will be rinsed off. Water soluble quaternary ammonium compound, made from guar gum. This is an ingredient that was in a conditioner that flaked up when I used enough product to keep my curls clumped. If you are going to rinse the product out of your hair, this ingredient is fine. If you are planning on leaving this on your hair, this may gum up. T
See also: Quaternary Ammonium Compound
Source(s): Begoun

You can find her page here and click the sources.

This sounds promising, considering that I don't use a leave-in and will rinse out the conditioner (and needless to say, the shampoo as well). I will do some more research though.
F - LP - HD - NE
Fine, low porosity, high density, normal elasticity
Hairtype 2c

Low poo: Petal Fresh Organics Rosemary & Mint Volumizing Shampoo
Protein: IAGirl's gelatine treatment
Detangler & LI: KCKT
Styling: KCCC

Beauty Is Not a Number