Audio dropouts ruined my recording

I did a one and a half hour recording and several large 10 seconds portions just are silent. This is imperative that I find the raw files or something because I cannot redo this file! How do I get the missing audio bits back!?!?!? Please let me know ASAP!

Without a lot more information it is not possible to help you.

Why is that? What are you recording? What equipment are you using? Which version of Mac OSX, Which version of Audacity?