As you mention, the SCL and SDA lines should idle high, so there is definitely something fundamentally wrong with the SCL. As a commenter said, there also seems to be cross talk occurring since the SDA going high causes the SCL to glitch.
- Are you sure the SCL line you've wired up is the one it should be?
- Verify you are using the right I2C interface on the pic (I2C1 vs I2C2 etc)
- Please verify you're calling I2CSetFrequency and I2CEnable (and with the right interface)
I've listed more info about I2C and typical problems in a separate article: http://chipscoop.blogspot.com/2012/08/understanding-ic-and-some-typical-uses.html