I've used Multipool's services for ALT coins and it seemed to be on the up and up. Blocks were solved and payments made. The above concern regarding BTC was my main concern and that's why I mentioned it. I specifically asked how many blocks they solved at other pools and it was mentioned that they didn't know because the other pools didn't report that information.

I don't think their users' gear is bad or that they are intentionally withholding blocks. It may be most likely with their proxying of hash power. It we take a look at that for a minute, is it possible that a block could be solved, but due to timing of sending the result to the network, it was being preempted by another pool solving the block? Or would we simple see an increase in orphaned or invalid blocks?

Some time ago, I thought someone mentioned that by solo mining, if you didn't have a priority connection to relay found blocks, even though you might find blocks, you'd have a better chance getting them accepted as valid by the network by mining with a larger pool.

Any clarity on the above is appreciated.