Software problem or hardware problem?

[codebeat-nl]

1. Uploading a sketch results almost always in a flash write error -1

Running Digispark Uploader...
Plug in device now... (will timeout in 60 seconds)
> Please plug in the device ... 
> Press CTRL+C to terminate the program.
> Device is found!
connecting: 16% complete
connecting: 22% complete
connecting: 28% complete
connecting: 33% complete
> Device has firmware version 2.2
> Device signature: 0x1e9311 
> Available space for user applications: 6650 bytes
> Suggested sleep time between sending pages: 7ms
> Whole page count: 208  page size: 32
> Erase function sleep duration: 1456ms
parsing: 50% complete
> Erasing the memory ...
erasing: 55% complete
erasing: 60% complete
erasing: 65% complete
> Starting to upload ...
>> Flash write error -1 has occured ...
>> Please unplug the device and restart the program.

2. Most of the analog ports cannot be used:
   setup:

for( int i = 17; i < 25; i++ )
  {
    pinMode( i, INPUT );
  } 

loop:

for( int i = 17; i < 25; i++ )
  {
    mySerial.println( analogRead( i ) );
  }

Serial monitor output:

 for A7 pin 17: 287
 for A6 pin 18: 295
 for A5 pin 19: 63
 for A4 pin 20: 63
 for A3 pin 21: 63
 for A2 pin 22: 63
 for A1 pin 23: 195
 for A0 pin 24: 63

Only pins A7 and A6 seems to do something, reacts when put a finger on it. So what is going on?