I have had a similar issue with Asus laptops (a K53E previously, now a B43S). To the best of my knowledge, it's a kernel issue. When I was running Fedora 16, with the 3.3.6 64-bit kernel on the B43S, I had no issues with suspend. I assume this would be the case on my K53E as well, but I just transferred the hard drive and RAM from one machine to the other. On the stock 32-bit Linux Mint 13 kernel or the 32-bit PAE kernel (which I'm running), the problem is present.
Problem is, I've tried upgrading the kernel already. Linux 3.4 32-bit PAE did weird graphical things once and HATED my wireless card. Linux 3.3.6 32-bit PAE from the Ubuntu PPA worked once, then on the second boot I got a kernel panic (analogous to the BSOD in Windows) after I logged in. While upgrading a kernel from the Ubuntu .deb files isn't hard (there's a lovely sticky thread here
about it), it's VERY risky considering how fundamental the kernel is.
If you're intrepid, by all means play with newer kernels and see which one fixes your problem without rendering your system unusable. I'm not sure if there's a stability difference between the 32-bit, 32-bit PAE and 64-bit kernels, but I'm not brave/foolish enough to mess with the kernel that much
Hopefully this answers your question, even if it's not a surefire fix at present.