Hi BendyLady - I wouldn't have got the translation you mentioned either

.
I really like Mr. Desikachar's book The Heart of Yoga which includes his translation and commentary on the Sutras.
Regarding the 2.10 he says:
Having described the obstacles that prevent clear perception, Patanjali indicates what should be the attitude of one who is keen to reduce them.
When the obstacles do not seem to be present, it is important to be vigilant.
A temporary state of clarity should not be confused with a permanent state.
Hope it helps.