Hmmmm, I have no problems when I make small amounts, although I also don't have problems making large batches and keeping it in the fridge. You might have to try different kinds of pastas as well. I find that rice or whole wheat pasta don't keep as well (figures, the healthier ones

). The kind I buy is an organic veggie pasta (it's wheat pasta, but made with beet juice, spinach, etc so it's the coloured kind) and I buy rotini. I make the whole package or half the package according to directions, then stick the remainder in the fridge and it's good for the week. Also, I think if you over cook it and it's a bit too mushy, that's when it gets sticky. Another tip is make sure you rise the pasta with cold water immediately after cooking it, or else it will keep cooking and again will get mushy and sticky. Shocking it with cold water will harden it up a bit.
It's actually great to have around because I throw it into soups, make pasta salads, or use it as a meal in a pinch. For example last night DH was working late, and I realized I didn't have anything prepared for dinner. But I did have a bag of pasta I had cooked two days earlier. So I chopped up a bunch of veggies, sauteed them with some garlic and pesto, and threw in the pasta. Simple, fast meal in a snap!