Debugging suspend problem with pm-trace

Have a computer which has long been unable to suspend ( hangs on resume ) and decided to try and investigate. Using the trace functionality to try and identify the problem driver I end up finding the following:

[    1.110545] PM:   Magic number: 5:864:888
[    1.110645] memory memory327: hash matches

What on earth is this telling me? It's consistent - every single resume results in the same crash and the same has being flagged - do I have dodgy memory?

I've run the memtest86+ which doesn't come up with any problems on this machine - though I can't recall if I allowed it to run for the full 8 cycles. Surely I'd be getting random crashes with dodgy memory - I'm not doing so.