Pool light fixed and repaired on the bulb but it goes off again

I have an inground pool with 1 light. I replaced the bulb and then it was sealed tight well with all the grease, lids and rubber sealer. I had it run for over 2 weeks and then it went off again. The main power switch is also new. It turns on but kinda of at the middle of it. Is the bulb bad? I had people that replaced the bulb which lasts for years and years but mine is going down ever 2 weeks. I cannot pay $18 for every 2 weeks. Is my main outlet then the problem and if so how to fix this. I can pay anyone to come down here to fix it. Let me know if the problem is actually the light. I have the Hayward kind of light but regular and bulbs from intheswim for $15 or 20.
http://www.intheswim.com/p/hayward-replacement-lights

Check to see if you have water inside the light socket. Normally you replace the rubber seal when you open the light to replace the bulb. Also, you don't normally use grease or rubber sealer to my knowledge.

Otherwise it sounds like it could be a bad switch, or corrosion on the contacts in the light socket. Possibly a bad bulb, but I am guessing not.

Before I switched to an LED light in my pool I bought pool bulbs from 1000bulbs.com. Any bulb related seller (even amazon will do). Pool stores - even online ones like intheswim.com charge a premium for pretty much everything they sell. I think I was paying around $2.50 for pool bulbs.

Can I use regular Flood Light for say outside the garage. I remember once about 6 yrs ago a pool guy (friend) came and he replaced it using regular flood light and it worked for 3 years day in and out with no problem. Where can I find gasket for the pool light? The main switch (with all the pool pump, lights, outlets) is fine but the one controllling the pool light get in the middle but the other switches are all fine. Why is that so? The circuit I use was also all brand new. What is causing it to trip like this?

If there is water in the housing it will cause a short. That will cause the breaker to trip.

So long as the flood bulb fits, is the right voltage and wattage I don't see why a regular bulb wouldn't work.

You need to know which hayward light you have. There are many hayward lights, and a variety of lens gaskets. Looking up the light information will also likely tell you what wattage bulb your light is rated for.

Here's some hayward gaskets: http://www.amazon.com/s/ref=nb_sb_ss...rd+lens+gasket

Thanks so much. I am going to try again and see what is going on... I appreciate the time taken to look into this.