MacBook not recognizing HardDrive after freezing and crashing

Question

This is the second time I had this problem since I bought my macbook (from the online apple store) at the start of August.
What happens the first time is that I leave to go do something and leave an application (such as Itunes) open on my computer long enough for the computer itself to go to sleep. Generally, this isn't a problem for me as I go for days without shutting down my computer (most recently for finals). But for these two times, (the first being in september), I come back to my computer to be greeted with a totally frozen machine. Though it will light up so I can see the screen and the mouse moves, I cannot close anything and commands will not work. after 15-20 minutes of waiting for the computer to recognize the quit command, I manually shut down the computer and let it sit for an hour or so.
Upon booting the machine back up, I am greeted with a blank gray screen that seems to go unchanged for a long time. Finally, I get a single folder icon with a question mark that flashes, stating that it cannot recognize the OS.
Now, the first time this happened, I was still under the phone service from the new purchase so I called applecare and spent close to an hour an a half with the rep on the other line and we tried dozens of ways to try and access the hard drive, none of them worked. He thought it might be soemthing with the hard drive connection itself so I sent the computer off to a repair store and recieved it back within a week, and I haven't had any complaints since. This was in september.
Tonight, I come back and my computer is frozen. I try everything I can to quit the programs open (itunes, ichat, word) and nothing works, so I force quit and wait an hour. I get the folder icon/question mark again, so i shut down the computer and wait two more hours. This time it boots up long enough for me to check my email and try working on a project in word. I go to open ichat and it freezes again. Now it is only presenting me with the folder/question icon.
The only thing that is similar between these two cases is that they both occured when I need my files the most for projects, and I would hope fate isn't against me. I tried to find some way to request a direct mail/pick up again on this site but I'm having trouble navigating it.
Has anyone else had this issue? The last time this happened, the invoice seemed to indicate that they replaced the cables and possibly some part of the motherboard and/or cpu (I had a hard time decifering the shorthand). I do not have my osX disc with me because I'm on Christmas Break and I left all my CD's at school. Does anyone have any suggestions with what to do? I am going to back up everything if it gives me a chance to, but I don't think whatever is wrong with it was fixed last time and I'm starting to think I have a faulty computer.
The only programs that start on startup (this site this may be a cause) is my alarm clock, Auroura, (sp) which takes little CPU space and even a smaller amount of ram.
Suggestions? Other stories?

Answer 1

Thanks for the help, but nothing is working. Even when I had the disc and was online with Apple Support, nothing shows up. I cannot start the computer in safe mode, or in single user mode, or anything because it says that I don't have a hard drive so it recognizes nothing. When I had the disc and tried to use disk utility, it only gave the option of repairing the DVD itself, and said that there were no other drives present on the system.
I know of one other person who had this problem at my school, but his cleared up within the day. Mine doesn't seem to be doing that.
As far as my computer is concerned, it has ram, but no OS, and more importantly, nothing from which to get information off of.
This is my first Mac purchase, and the first time anyone I know has chosen a mac (with the exception of college friends). I love the operating system, and from what I've read on here ,the newest generation of Macbooks are much more stable, but I'm starting to get really frustrated with my computer dieing like it is. Hopefully I'll be able to run down to an apple store (the nearest is a little more than an hour away) and get it fixed again, but I don't want this to be a reoccuring problem, which it seems to be. Hopefully, if it is a hardware issue, they'll upgrade my computer accordingly. I can't afford to do so myself at the moment.