I guess i know what's causing this, will fix it in next ver.
You guys get a job timeout before this, am i right?
Are you setting it manually in pools config?
If not, can you try to put
"job_timeout" : 900 , that is 15 minutes, and test to see if you still get timeouts and invalid job rejects?
If no timeouts i will know this was the problem

thanks
example:
pools.config{
"pools" :
[
{"pool" : "xmr-eu1.nanopool.org:14444", "wallet" : "4A5hJyu2FvuM2azexYssHW2odrNCNWVqLLmzCowrA57xGJLNufXfzVgcMpAy3YWpzZSAPALhVH4Ed7x
o6RZYyw2bUtbm12g.donation", "password" : "x"
, "job_timeout" : 900}
]
}
I was getting rejected shares with the new miner with normalv7 (I was mining heavy with the previous miner so can't comment if this is specific to the new miner). Never noticed the job timeout option. Tried it with 900 and I see no rejected shares in the last 6+ hours.