Could you try installing the 32bit version of the client for me? I've found that some systems although running a 64bit OS for some reason force java to run at 32bit.
http://cdn.mmoui.com/minion/Minion2.0.11_x86-beta.exe
Can't say that will work for you but its worth a try (and please let me know either way). It fixed the jvm.dll error people were getting. We are working on getting more error logging during the splash screen so we can try and catch this error. However it will be about a week yet (maybe more) before we can get that logging into Minion.