Yamaha 1300 Tourer - Yamaha 1300 Tourer Fansite

Hello all. My name is Timothy and I'm fairly new to this site. I bought a '08 V Star 1300 brand new back in May. It's my first bike and I have thoroughly loved all 5k miles I put on it this summer. I've developed somewhat of a problem though. I performed the break in oil change at 1k miles. Did the work myself and had no problems. About 1,500 miles after the oil change I noticed a leak had developed on the bottom of the engine, and best I could tell it was coming from the oil filter. I didn't know how much had leaked out and I don't really trust the sight glass so I decided to be on the safe side and do a complete oil change with new filter. After I did this everything was fine for about another 1,500 miles and then the same thing has started again. The guys at both Yamaha dealers I've been to have never heard of anything like this. The filters are always tight when I go to unscrew them. I hand tighten them on and am always sure to put oil on the filter ring before installation. Also, I check each time to make sure the old rubber ring did not stick to the engine. It will actually leak extremely slowly when its sitting in the garage (few drops every day). Naturally I can't really tell how much it's losing on the highway, but according to the sight glass, you can barely tell anything is missing.

The bike is still under warranty, and there's a couple other warranty issues that need to be dealt with (speedo is 5mph fast) so I will be taking it into the shop soon. I'm just wondering if anyone else has ran into this problem. It seems strange that a brand new bike that isn't rode irresponsibly or hasn't been damaged would leak oil in its first season. Thanks for any thoughts or insight on the matter.