Guys, I really need some help. I am stuck with this problem that should not
happened and in my understanding should happened the other way around. Could
somebody help me. I include some scenario that I can't solved. Thanks

Is there is an error in the formula or else?

Scenario 1

1 01/01/2006 -5,00E+08
2 01/02/2006 5,00E+07
3 01/03/2006 5,00E+07
4 01/04/2006 5,00E+07
5 01/05/2006 5,00E+07
6 01/06/2006 5,00E+07
7 01/07/2006 5,00E+07
8 01/08/2006 5,00E+07
9 01/09/2006 5,00E+07
10 01/10/2006 0,00E+00
11 01/11/2006 0,00E+00
12 01/12/2006 0,00E+00
13 01/01/2007 -1,00E+07
14 01/02/2007 0,00E+00
15 01/03/2007 0,00E+00
16 01/04/2007 0,00E+00
17 01/05/2007 0,00E+00
18 01/06/2007 0,00E+00
19 01/07/2007 0,00E+00
20 01/08/2007 0,00E+00
21 01/09/2007 0,00E+00
22 01/10/2007 0,00E+00
23 01/11/2007 8,00E+07
24 01/12/2007 0,00E+00 -9,8335% = irr function)

Scenario 2

1 01/01/2006 -5,00E+08
2 01/02/2006 5,00E+07
3 01/03/2006 5,00E+07
4 01/04/2006 5,00E+07
5 01/05/2006 5,00E+07
6 01/06/2006 5,00E+07
7 01/07/2006 5,00E+07
8 01/08/2006 5,00E+07
9 01/09/2006 5,00E+07
10 01/10/2006 0,00E+00
11 01/11/2006 0,00E+00
12 01/12/2006 0,00E+00
13 01/01/2007 -1,00E+07
14 01/02/2007 0,00E+00
15 01/03/2007 0,00E+00
16 01/04/2007 8,00E+07
17 01/05/2007 0,00E+00
18 01/06/2007 0,00E+00
19 01/07/2007 0,00E+00
20 01/08/2007 0,00E+00
21 01/09/2007 0,00E+00
22 01/10/2007 0,00E+00
23 01/11/2007 0,00E+00
24 01/12/2007 0,00E+00 -11,8678% = irr function