I have some nets near me that stay wet for days after rain and you cant really tell how your bowling. Its quite frustrating because they just skid on and I reckon you really need the feedback to know how your going.
Its unfortunate that you can't get down the nets more often. I have found that getting down there at least once every two days and sometimes 6 days a week has been the biggest help in my action improving. I found when I only got down there once a week or so it was exactly as you said, you forget bits and remember bits that worked last time and by the end of the session you've only got back to where you were last time at best and haven't really improved.
Its funny how you can bowl your best deliveries consistently and then you put the camera on and they start going everywhere. Happens to me all the time.
Haha yeh the camera is a curse! The great thing is though that it sort of replicates pressure that you might face in matches, so the pressure to produce that perfect delivery for the camera isn't dissimilar to the pressure to produce it to a batsman. Obviously the bad balls don't get punished by the camera though.
Once the weather improves a bit, and with the clocks going forwards this weekend to give an extra hour of sunlight in the evening, then I'll be able to get down the nets every day or 2 (weather is the killer there though, because it will undoubtedly rain for most of April). At present I'm still playing indoor generally one night a week on average, and we have indoor nets one night as well. I need to hit the gym at least twice a week from now to the season start to get my fitness up (although high intensity net practice probably substitutes for one of those sessions), so I just need to try and cram my practice in amongst all of that, plus everyday life. Professional sportsmen don't know how easy they have it. I'd love to spend all day everyday just training, and getting paid to do it!! They should stop whining about hectic schedules and enjoy it whilst they can.