Aren't there memory leaks in cpuminer 2.4.3 win64 version? Its virtual memory increases roughly 4GB per day while mining 1MB blocks. When remote node restarts these GB disappear and miner then tries to resolve host with four random characters even it was configured to connect at 127.0.0.1.
You are right, I just checked and there is indeed a memory leak in the GBT code. I'll push a quick fix to GitHub shortly. Hopefully I'll also be able to publish new binaries soon.