Bought my wife a high-end laptop with Windows 8 64 bit for Christmas. Of course she really didn't need a laptop with a graphics card, but she got one none the less if you get my drift and I think you do. Anyways I got Instant Player and Deep Matrix working on it.
I can't say it went flawless.
The first few times I tried to download Instant Player on her wireless laptop Windows 8 told me it was corrupt and it wouldn't install. So I tried to download it on my own cabled Windows 7 64 bit system and just transferred it over using flash memory card and it installed fine. I installed the 64 bit version of Instant Player.
The Sun JRE is 64 bit as well, which like Windows 7 is different from the 32 bit JVM for Internet Explorer.
After those two installations, critical stuff functioned as it should have without security problems.
The Deep Matrix client window had some problems though. I could go into ghost but couldn't get out of it unless I beamed to a bot or an object. Also, the Enter choice for switching worlds did not want work either for changing rooms.
I gotta admit all the Java GUI for the DM client IS of a depreciated nature and I wonder if that is the problem.
But DM does indeed work on the latest and greatest with albeit a few nuisance bugs.