Periodic crashes

[ch4ot1c]

buffer.js:240
    buf.copy(buffer, pos);
        ^

TypeError: buf.copy is not a function
    at Function.Buffer.concat (buffer.js:240:9)
    at /root/bsha3-pool/node_modules/stratum-pool/lib/merkleTree.js:54:37
    at Array.forEach (native)
    at Object.MerkleTree.withFirst (/root/bsha3-pool/node_modules/stratum-pool/lib/merkleTree.js:53:20)
    at JobManager.processShare (/root/bsha3-pool/node_modules/stratum-pool/lib/jobManager.js:216:60)
    at null.<anonymous> (/root/bsha3-pool/node_modules/stratum-pool/lib/pool.js:506:46)
    at emitTwo (events.js:92:20)
    at emit (events.js:172:7)
    at handleSubmit (/root/bsha3-pool/node_modules/stratum-pool/lib/stratum.js:159:15)
    at handleMessage (/root/bsha3-pool/node_modules/stratum-pool/lib/stratum.js:72:17)

node -v: 4.2.6