That is a 4 year old camera. I'm sure your warranty has expired.
The repair/shipping might be close to the cost of a new digicam.
After you make the decision I would consider a flexible waterproof housing that is easy to fit in your backpack. You can check out the waterproof pvc bags made by Ewa Marine at B&H Photo.
Here is Ewa Marine's cross reference list for all Olympus digital cameras. However the c-2100 has been discontinued.
Other option to consider, check out the Olympus Stylus 300 it's weather resistant for those rainy days.
Retails for $ 279.