When using KeePassSync in SCP/SFTP mode, the PuTTy commands invoked don't force the SSH protocol. This causes problems when the 'Default Settings' saved session in the main PuTTy application has a protocol other than SSH selected (for instance telnet). This should be as easy as adding '-ssh' to the command line strings for plink.exe, and '-scp' for the command line strings for pscp.exe. Both of these would be set under KeePassSync\Providers\SFTP\main.cs
Bug #31 may be affected by the explicit setting of -scp, so this may need to be specified as an option.