A friend of mine asked me to take a look at an issue he was having with no wet runways showing in P3D v2.5 and what I have found was kind of interesting. Keep in mind I am not a P3D user yet but definitely considering the switch. I have fsxse where I want it to be, so back to the alleged bug.

 

Scenario

You open P3D v2.5 at the menu you choose your settings, weather, etc... start the flight, its raining and no wet runway. :(

 

Solution

Disable the startup menu on startup, restart the sim and within the sim create a flight. Now you should have wet runway effect.

or just change you p3d.cfg not to show start menu.....

 

 

Please note this issue did not exist in v2.4 and I hope somebody can forward this to LM to get fixed.

 

This issue is not a big deal for me but for those people who like wet runways to show (like my friend), I hope this may help you saving hours of troubleshooting....

 

 

 

 

Yep, this bug is easily reproducable, and the fix is indeed to not use the Scenario Manager.

Yours was the first report I saw on it, but it's more than likely related to this:
http://www.prepar3d.com/forum-5/topic/v-2-5-aircraft-texture-dullness/

As you will notice, this has already been fixed in LM's internal builds, after they had a lesson from Sir Garwood. B)