There is a possibility that your starter was not completely activated when you put it in the fridge, but this is probably not the case. If it was expanding to the point where it was at least doubling in size within anywhere between 3-7 hours you should be fine.
Don't underestimate the effect that temperatures can play on your recipes, especially when using wild yeast cultures. I know that around the area that I live (Boston) things have been very cool lately, tonight in the low 50's even though it is almost June. Temperatures like this could really slow down your starters rise times. Make sure your culture has at least doubled and no more than tripled before you use it in your recipe. After you have mixed your dough wait as long as it takes for it to double (but no more) in size before baking. If the dough is extremely sour or off tasting, then you could be having some issues with your culture.
Should you find that your dough is too sour all is not lost. You can still try to revive your starter by giving it lots of food and keeping it out of the fridge for a while. Don't wait too long in between feedings. Let it go through a bunch of life cycles and see if things speed up. You can also feed a higher ratio of food to culture than you usually do, just make sure to wait for a full rise and slight fall before re feeding. Another trick to perk up a starter is adding a small bit of rye flour which is a much happier environment for your culture to live in than wheat flour.
Good luck my friend and please feel free to check back with more details.