vpoolserver,
Just a few notes - I think most of your bugs are coming from mmcFE. Connecting to your servers with miners works, but it sucks for us in the USA because of latency and we lag out - that's not something that can be helped though, and it appears you have ppcoind and pushpool set up correctly.
mmcFE took me a few days of playing around with to get it right and I am still not very happy with it. The biggest bug I dealt with (which you may want to check) is how you are computing difficulty. When you use the getdifficulty api with ppcoind, it does not differentiate between stake block difficulty and proof of work difficulty. For example, difficulty can be 300,000 from proof of work, then drop down to 9,000 for a few consecutive pos blocks, then back up to 300,000 for another pow block. When you use getdifficulty API, you get an array instead of a double (like you would with other coins) - this array contains both the latest pow and pos values from what I remember. You have to explicitely call the 'proof-of-work' element from the getdifficulty array.
Anyway we will probably both run into future bugs because mmcFE was not built for ppcoin, and ppcoin has many different things than BTC. After working on this myself, I understand that your mining pool was probably misconfigured\had bugs rather than you were trying to explicitely scam people. Let me know if you want to work on ironing bugs out together, we have essentially the same code now. Also, I switched my domain from vPool.me to VuxilsPool.com, so we can avoid confusion on that part.
Best,
Vuxil