Right, I just checked.
Tournaments like Rotterdam, Bangok, Doha and Dubai 2006 pre final certainly inflated his numbers and contributed to the streak. That's 19 wins right there.
However, there are 2 things that I want to mention:
1. He also beat Nadal in the final of Miami who would become no. 2 shortly after and Ljubicic did play well early in the year and was stopped by Fed a lot. He would enter the top 10 anyway. Also beat Davydenko in Rotterdam, another guy who would enter the top 10 later in the season. Also beat Nalbandian who was ranked no. 11 and would end the year as no. 6 anyway. These things need to be taken into account.
2. Fed's consistency against guys outside the top 10 finally improved after 2004, a year in which he only lost to such players. So that makes his streak more impressive because of this.