I often post bargains but as of late I have posted less of them because some companies (like OfficeMax) have gotten much worse in terms of their rebates through Rebates HQ.
This article is worth reading if you haven't already seen it:
Out of perhaps two dozen rebate submissions, I've gotten stiffed twice. I guess that's just the price one pays. One was for a $30 rebate on an Acer wireless keyboard (great keyboard, though; I'm typing on it right now, years later).
The biggest hassle I had was with a WD 120GB drive. It was one of those deals involving multiple rebates. My net cost was supposed to be $16 after originally paying $170. Rebate house wouldn't approve the big $100 rebate, saying I had submitted a "packing list" rather than the requested "packing slip." They were right. Problem was, I didn't have the packing slip any more. They suggested getting a duplicate from Dell, which I then requested. Dell said they had purged their database of such documents, but a sales order copy would suffice. Rebate company said no, and so on...
Ultimately, I reached someone in Customer Service, and after making it clear that I would not go away, she immediately authorized a "good faith" credit to my credit card for the $100. Based on that, I would definitely buy from Dell again, hopefully keeping ALL the documentation next time.
You've got to keep copies of your receipts, have a system for following up when the time expires, and be willing to do it. I've always gotten my rebates, but it has required a few minutes of time to gently remind the rebate headquarters that they owe me money.