Dear Gustaf,
I believe all issues we have been facing are gone.
They were caused by two errors:
1. memory allocation problem (in dstring.c)
2. bad handling of the WSASend call.
I do not know if you saw it or not. But looking into possible causes for these problems I noticed that EINTR is not handled in a generic way as EWOULDBLOCK and EINPROGRESS. Perhaps it would make sense to normalize also EINTR.
