Could sand and a little sea water damage my iPhone's dock connector?

Well the story goes like this:

I was at the beach last January with a few friends (wooho)! I had the phone on a pocket and I was with my feet into the water when a wave came in and slightly got into that pocket, I took the cellphone out, it was slightly wet (it was less than 2 seconds). I tought it wasn't so bad because the phone didn't seem wet at all! The phone was drope one or two times into the sand too but nothing too serious... so... I had this iHome at home (duh) and before this trip it controlled my iphone perfectly. When I came back from my trip the iHome didn't control the iphone any longer but with a trick it could still reproduce the music (without any type of control over it). That type of devices that control the iphone via dock no longer works with my iphone 4 but it still charges and syncs. So I went again to a trip to the beach this month and this time the phone didn't get wet but it got dropped into the sand one more time... now it still charges and syncs but apparently video doesn't come out any longer via special cable to my kenwood radio BUT it DOES WORK with a special cable on a Pioneer. I'm very confused and don't know what to do. What could be the problem and what should I do? Should I change the dock connector?

Thank you for your time and help