v. 1.5.6 still have problem - if some gpus stop hashing the miner not hangs but just stoped and not showing any information further. So if i see that and press some key (space or h for example) it will show that gpu's hash speed is 0 and make reconnect to pool and after it will work good for some time.
sorry but i dont understand,can you turn on logging and share that?

so marked area is when i see that one of rigs do no sending shares more than 2 minutes. Miner just not doing anything after returning to
user mining and than i have to press H or S and see hash speed is 0
it's v 1.5.6
p.s. i have to admit that in v 1.5.6 this situations happens not often
after that is all good.