here's a test.c:
#include <stdio.h>
int main(int argc, char **argv)
{
	while(--argc) {
		printf("arg%d=|%s|\n", argc, argv[argc]);
	}
	return 0;
}

old behaviour:
BusyBox v1.15.3 (2011-07-12 09:44:37 CEST) hush - the humble shell
/tmp # foo=" a "
/tmp # bar=" b "
/tmp # ./test.ppc $foo $bar
arg2=|b|
arg1=|a|
/tmp # 

new behaviour:
BusyBox v1.18.5 (2011-07-27 10:16:21 CEST) hush - the humble shell
/tmp # foo=" a "
/tmp # bar=" b "
/tmp # ./test $foo $bar
arg4=|b|
arg3=||
arg2=|a|
arg1=||
/tmp #