I understand that when it's hot the cap has a valve to release pressure build up which could cause this but it even happens when the tank is less then half full, or in the morning when it's really not that hot in the garage I notice it. I've taken to carrying around an baby diaper cloth (new, not used

Finally, the first time I filled the tank I did over fill it and when I got on and leaned her to pick up the side stand gas spilled out of the cap. I quickly cleaned it up and rode pretty slow, didn't make any quick stops or sharp turns and took the long way home so that I could burn some of the gas up. This was about 3 weeks ago and I've had to put fuel in it since then.
Sorry for the long post, I can get a little long winded at times when trying to explain something through writing, it’s a bad habit I got from writing processes at work.