Hi, I have a leviton slide dimmer controlling 4 pot lights with gu10 bulbs. There is also 6 receptacles on this 15 amp circuit. I had a regular 2 pole switch on there, with no problems. When I converted to dimmer, the dimmer popped. The lights still work, but the dimmer does not. I am assuming the transformer popped. The gu10's are only 50 watts and the dimmer is 600 watts.

https://www.leviton.com/en/products/6672-1lw

Specs say Dimmable LED lights are fine, so that means your lights are the ones at fault. Although marked dimmable, they are aren't. Swap the bulbs out for another make. Also if you read the FAQ on the lower section of the page, there are secret switches hidden behind the slider. Also interesting to me is that on the top metal fixing plate it shows
LIGHTED OPTION
ON - OFF

what do you know as "regular " bulbs
are they low energy or incandescent

YOU NEED TO REEMPLACE THE DIMMER, SOMETIMES SWICHTS GET DUST IT AND CORROSIVE SPECIALLY IF ITS OLD.

Any off-the-shelf GFCI sold today with work on 12-2 wire:
By code, 12-2 wire should be connected to 20 amp circuit breaker, but typically most switches and outlets wired to that circuit are rated 15 amp. Amp rating is printed on electrical devices.
Leviton 15 amp 7599-W:
http://www.amazon.com/Leviton-7599-W-Receptacle-Feed-Through-SmartlockPro/dp/B000VYO9MU/ref=pd_cp_hi_3
Leviton 20 amp 7899-W
http://www.amazon.com/Leviton-7899-W-SmartlockPro-Indicator-Wallplate/dp/B000N663PM/ref=pd_cp_hi_0
Wiring:
http://waterheatertimer.org/How-to-wire-GFCI.html

Just tripping the breaker should no affect your dimmer unless maybe malfunctioning or wired incorrectly or loose connection. It is hard to wire incorrectly, for there should only be two wires attached to the dimmer? Replace dimmer and make sure wiring is correct if not sure about wiring yourself contact local electrician for your safety. There are very good instructions inside the switch packages, make sure to buy a quality switch, Leviton is a good name I would lean towards faulty switch or loose connection but I'm not there. Good Luck Karen....

The National Electric Code (NEC) does not directly state the number of outlets per general purpose circuit for a residence. They only state that "x" amount of sq. ft. must have "y" amount of circuits and that they be evenly distributed. The number of outlets is then limited by physical outlet spacing rules.

However, a rule of thumb is the points system. A 20 amp circuit is 20 points. A regular duplex receptacle is 2 points and a light is 1 point. You can have any combination of receptacles and lights that add up to 20 points. For example, 10 duplex receptacles x 2 points = 20 points. Or, (8 duplex receptacles x 2 points = 16) + (4 lights x 1 point) = 20 total.

The concept is the same for a 15 amp circuit except the total points will then be 15.

So, the answer is about 10 receptacle outlets per 20 amp circuit. In a pinch, you can stretch that to 12 or so and still be OK.

Google-search: florescent slide dimmer
You have 320 Watts, 120 volts, and the circuit uses 2.6 amps.
Volts x Amps = Watts.

1) The florescent slide dimmers seem to cost $100-120

2) If you search for florescent dimmer, the cost is lower than the slide dimmer.
Leviton sells for $50
http://www.google.com/products/catalog

http://www.instockelectrical.com/vgfs15-cooper-15-amp-gfciswitch-de1515.html

http://www.amazon.com/Leviton-7299-NI-SmartLockPro-Combination-Receptacle/dp/B000T8GWUK

If there are 8 in number t8 then there can be 8 wired.

Questions to answer so I can answer/resolve your problem:

1) Is this a rotary style dimmer?
2) Is it a toggle or slider type?
3) Is this on a 3-way circuit (that has 2 or more switches that can turn the lights on or off)
4) Is this on a single switch circuit?
5) Is this a brand new dimmer switch?
6) Is this an old dimmer switch?
7) Are the light bulbs in the spots regular incandesant or halogen bulbs?
8) Are the light bulbs in the spots CFL (compact flouresent lamps)?

With this information, I can tell you what the problem is:

If you answer "YES" to #1, and or #6 then the dimmer is faulty and should be replaced.

If you answer "YES" to #8, then you have the wrong dimmer for the bulb type, as CFL's require a specific dimmer type in order to dim them.

Please provide some more info and maybe we can help you figure out what's wrong.

Hope you find this Very Helpful and best regards!