Some possible workarounds are:
First try using cifs:// instead of smb:// to connect to the server volumes.
If that doesn't help, then there is a way to change all connections that use SMB1 by entering this command in Terminal: To restore the default SMB2 you simply need to delete the newly created configuration file (nsmb.conf) with the command: Both workarounds force OS X to use SMB1 as a network protocol instead of the default SMB2 used by OS X 10.9 (Mavericks). While the first is an ad hoc solution the second is a persistent but reversible configuration change (for this user account). SMB1 is slower than SMB2 but stable.
[crarko adds: I don't have a way to test this at the moment, but I do recall reading that people have experienced some of these issues. If someone has a NAS device to test this with (especially if there have been problems) please let us know if either of these fixes helped.]