I won't presume to speak for lil (pleased to meet you!), but when I used to needlepoint in front of the TV, before the discovery of snack foods, I had the bad habit of making my first five or six stitches too tight, to hold down the loose end of the floss which was being looped into the underside. (Does that make sense?) Maybe you're doing something that's sort of the opposite, not consciously but making sure it's not too tight and ending up with too loose?
Other things to ask yourself is whether you're using the same brand of floss and the same cloth/mesh as usual.
To fix areas which are already done and too lose, consider inserting a length of floss into the loops on the back of the work, just to add some tension. My guess is that it will seem too tight when the needle is going through, but might be fine once it's only floss back there.
Good luck!
Maryn, who hasn't needlepointed in a long time but should