ATTINY45 ADC1 PROBLEM

There is a thread about this topic:

http://arduino.cc/forum/index.php/topic,124139.0.html

The analogRead are refered by the ADC number

Physical pin 7, Analog #1
Physical pin 2, Analog #3
Physical pin 3, Anallog #2

The 100nF capacitor between Vcc and ground are important when using the DAC

I tried your code and got these results:
If you remove this line, the LED will blink with normal strenght
pinMode(VoltsIn, INPUT);

2
3
4
5
5
6
4
5
4
4
5
6
11
28
44
84
132
199
210
216
216
236
276
334
368
383
392
401
428
470
573
650
1022