AC/DC Power suply and ArduinoMega+Ethernet.

Hello there, i amhaving some problem with power supply with my project, i use a Mega and ethernet shield,
i use a DS1307 , a DHT11 , and 8 PWM outputs of leds (power leds for aquarium with external supply ) and motors , I "feed" the Arduino with 7,2V 2amps AC.DC Wall mart and the arduino regulator is not getting hot.
My problem is that , when i dimm OUT or DimmIN the leds i get some picks for 0.01 seconds to the limit 255, like its flashing , in random times,
could someone suggest me what to do? what to measure? its not the code...

Oh No.. my bad! i found a bug in code.... so its totally my fault...

i just found that when i am reading the DS1307 hours, mins etc .. i dont use delay(1000) , so i get randomly false values for example
hour=45 , mins=85 ( in a millisecond) ..
When i use delay(1000) everything works like it should , the problem is that i dont want to use delay ...