You go to that factcheck.org site-- which is an ANNENBERG organization, just like the one whose board Obama and terrorist Bill Ayers served together on--and here's what SB 99 says

http://www.ilga.gov/legislation/fulltext.asp?DocName=09300SB0099lv&SessionID=3&GA=93&DocTypeID=SB&DocNum=0099&print=true

(a)  The   program   established  under  this  Act  shall
24    include,  but  not  be  limited  to,  the   following   major
25    educational  areas as a basis for curricula in all elementary
26    and secondary  schools  in  this  State:  human  ecology  and
27    health,   human   growth   and  development,  the  emotional,
28    psychological,    physiological,    hygienic    and    social
29    responsibilities of family life, including sexual  abstinence
30    and   prevention  of  unintended  pregnancy  until  marriage,
31    prevention and control of disease, including age  appropriate
32    instruction  in  grades  K  6 through 12 on the prevention of
33    sexually transmitted infections,  including  the  prevention,
1    transmission and spread of HIV AIDS, public and environmental
2    health,   consumer  health,  safety  education  and  disaster
3    survival, mental health and illness, personal health  habits,
4    alcohol,  drug use, and abuse including the medical and legal
5    ramifications of alcohol, drug, and tobacco use, abuse during
6    pregnancy,  sexual  abstinence   until   marriage,   tobacco,
7    nutrition, and dental health.

So what does factcheck.org say is false about this ad?

"'comprehensive sex ed' appears only once"-- IRRELEVANT to the charge that Obama voted for sex ed for Kindergartners, the topics that are to be taught to kids K-12 are named.

"instruction would be 'age-appropriate'"-IRRELEVANT to the charge that Obama voted for sex ed for Kindergartners, it is the TOPIC of STDs that is repellant, nobody imagines Kindergarteners would get slides from Gray's anatomy

"parents could opt out" -- IRRELEVANT to the charge that Obama voted for sex ed for Kindergartners, and as a practical matter kids would be taught about gonorrhea until their horrified parents filled out the paperwork

"the bill also dealt with other topics"--IRRELEVANT to the charge that Obama voted for sex ed for Kindergartners, he signed off on everything in the bill

"the bill died after Obama's committee voted it forward" ---IRRELEVANT to the charge that Obama voted for sex ed for Kindergartners, he got his say and he say YES

"Obama 'clarified' his views in 2004"---IRRELEVANT to the charge that Obama voted for sex ed for Kindergartners, he did so vote for a law that did say that.

so on the one hand you have the fact the bill called for sex ed for K-12, and Obama voted for it, and McCain's ad said so, and on the other hand, nothing to contradict it and lots of spin to put lipstick on that pig and fake outrage at how LOW McCain could be to mention the fact that Obama voted for a bill that called for "comprehensive instruction" on sex, drugs and tobacco.