The code below does not work the same on the new arduino 1.0 as with the old software. It should continously print longer and longer strings of ones (1111....)
BUT when adding four digits every time it just prints the following:
<
111111
2111111111
31111111111111
411111111111111111
51111111111111111111
>
It does however work when adding both three and five ones every time (111)(11111).
I have no explanation but it does represent a huge problem to the code i need to write.
For now I will just go back using the old software, but I guess this can be fixed for v1.1
Wasn't sure who to let know, but now somebody knows at least

int cnt=0;
String longstring="1";
void setup() {
Serial.begin(9600);}
void loop() {
cnt=cnt+1;
String add="1111";
Serial.print(String(cnt));
longstring=longstring+add;
Serial.println(longstring);
}