hey guys, I don't know what to do with this error. I've got r9 280x windows 7 x64

if I restart the miner everything is fine but from time to time I get this error and sia mining stops while eth goes just fine.

at first I get this:
13:48:49:091   1360    SC: http error #28.
13:48:49:091   1360    SC: Failed to connect to pool (sia-eu1.nanopool.org:9980), retry in 10 sec...

and then after alot of tries this

 SIA: incorrect job data size
SIAD invalid http response, wrong number of bytes received: 36
Response: {"message":"404 - Refer to API.md"}

here's my failover:

POOL: sia-eu1.nanopool.org:9980, WALLET: 5b63e39d182f778640a9165350eed3590a28e61a60a8583735c767e0c057b792e42033b978c4/worker, PSW: x, WORKER: , ESM: 0, ALLPOOLS: 0
POOL: sia-eu2.nanopool.org:9980, WALLET: 5b63e39d182f778640a9165350eed3590a28e61a60a8583735c767e0c057b792e42033b978c4/worker, PSW: x, WORKER: , ESM: 0, ALLPOOLS: 0
POOL: sia-us-east1.nanopool.org:9980, WALLET: 5b63e39d182f778640a9165350eed3590a28e61a60a8583735c767e0c057b792e42033b978c4/worker, PSW: x, WORKER: , ESM: 0, ALLPOOLS: 0
POOL: stratum+tcp://siamining.com:3333, WALLET: 5b63e39d182f778640a9165350eed3590a28e61a60a8583735c767e0c057b792e42033b978c4.wo rker, PSW: x, ESM: 0, ALLPOOLS: 0
POOL: siamining.com:9980, WALLET: 5b63e39d182f778640a9165350eed3590a28e61a60a8583735c767e0c057b792e42033b978c4.wo rker, PSW: x, ESM: 0, ALLPOOLS: 0

any ideas?