Help matching vocals and bgm?

Hey, guys! I'm new here, and have just made my UTAU, Okamine Akuchi. I'm having a problem though. I've been working for a while on KOKORO, and it sounds pretty good for my first try, I think~ But here's my problem:

When I try to mix the vocals with the music, I can't get them to match up. Kokoro is supposed to have a tempo of 140, I think. The UST I used has it all set to 65, so I change it to 140 due to it being WAY too slow. But when I match it to the actual Karaoke of KOKORO, even though the tempos match, my vocals are slightly faster than the actual song. Can anyone help me out on what to do for things like that, please?

I have Reaper, FL Studio, and a lot of other programs for this, so if you have any suggestions, let me know!

Any help will be greatly appreciated! Thanks!

NOTE: I have read the tutorials here, but I have a slightly different problem.

Try slicing the vocal parts in the FL Studio playlist. Then just move the parts around so they kind of sound more on time.

Use audacity, reaper or whatever you have at hand and select a long piece of the original song between two very caracteristic notes. Write down how long it is.
Now, select your UTAU wav version and do the same between the same two familiar spots. Write down this new time.

Do a (inverse) rule of three to see what should be your desired tempo in the ust.

time original song ------ T (your actual tempo in the ust)
time ust version ------ X (correct tempo)

X = T * time_ust / time_original

Example:
In the original song between the note A to the note B there are 100 seconds.
In your version of the ust with a tempo of 200, the time between note A and note B is 50 seconds.
Real tempo = 200 * 50 / 100 = 100.
Half the tempo, of course.

Keep in mind this trick doesn't work if there are changes of tempo in the middle -like a bad done midi that can be the case-.
And the bigger the selection, the more exact is the value of the new tempo.

When the tempo is correct do what LupinAKAFlashTH2 said as it's easier that trying to figure a correct silence for the start.

Thanks, I'll try to see if these will work~ :3 This is my first time using UTAU extensively, so I'm really nooby with this~ ^^;