In a network setup where several trusted peers run on a network, -connect'ed to a single proxy which connects to the outside world, the wallet resubmission mechanism is defeated.
If the proxy for some reason has a network hiccup at the time a wallet transaction is broadcasted the first time, it will never reach the public network. The wallet node will keep resubmitting, but as the proxy already has the transaction in its memory pool, it will not relay the announcement.
This issue was reported to me on IRC by thermoman, and the solution seems adding a config parameter to setting a trusted list of IPs/netranges for which invs are always relayed, even if they were already known.
I believe this in implemented.