...insurance company cover the damage? I told them it was probably done by a vehicle, and they said that since I'm not covered for collision that my policy does not cover this damage. Fact is I can't say for sure that a vehicle did it, and I pay a lot of money anyway for comprehensive damage. Should they cover the damage? Isn't collision only if both vehicles are in motion? thanks.

You can report it to your insurance company and they will investigate the cause of the accident. If they find that it was caused by a collision then they will not pay for the damage. Collision coverage applies to your motorcycle striking another vehicle or vis a versa, regardless if either vehicle was parked or moving. In order to be considered covered under comprehensive the damage must have had to have occurred by a limited number of other factors listed in the policy( ex. fire, flood, vandalism, theft, ext) Comprehensive is not as "comprehensive" as it sounds.

Also check your policy for Uninsured Motorist coverage. Since the cost is low, most people obtain this coverage and forget about it. Uninsured motorist coverage usualy pays for hit and run damage(other requirements may be needed such as a police report) Some states do not allow Uninsured motorist coverage to be sold though.