Yeah, I just picked all three light side choices, a total of what should be 250 lightside points, and I recieved a wooping 100. Nice how this place has been out for a year and it still doesn't work right.
This might happen if you were at 100 LS points from the maximum.
Was this the case?
Or did you see in the "quest complete" dialog box that you only received 100 LS points?
To further explain: if the "quest complete" dialog box shows 250 LS points, but you only received 100 LS points then that is because you could only "receive" 100 LS points before being maxed out. (Same happens with companion affection. If they are 10 points from being maxed out, and you receive 15 points for completing a quest they only receive 10 points.)