Howdy,
I'm having trouble creating even the simplest transformation to pull filenames from an sftp server. I have access to this server from other clients but cannot seem to get PDI to work.
The issue started when I pulled down a transformation from our internal code repository that works for all of our other developers. It reaches out to an sftp server and retrieves the filenames (then later does other things with these files).
However, when i try to run this transformation I get the following error:

2015/04/17 16:08:58 - Spoon - Transformation opened.
2015/04/17 16:08:58 - Spoon - Launching transformation [sftp test simple]...
2015/04/17 16:08:58 - Spoon - Started the transformation execution.
2015/04/17 16:08:58 - sftp test simple - Dispatching started for transformation [sftp test simple]
2015/04/17 16:08:58 - FileInputList - ERROR (version 5.3.0.0-213, build 1 from 2015-02-02_12-17-08 by buildguy) : org.pentaho.di.core.exception.KettleFileException:
2015/04/17 16:08:58 - FileInputList -
2015/04/17 16:08:58 - FileInputList - Unable to get VFS File object for filename 'sftp://pentaho:...@secure.mftexpress.com:22/TESTfolder' : Unknown scheme "StrictHostKeyChecking" in URI "{1}".
2015/04/17 16:08:58 - FileInputList -
2015/04/17 16:08:58 - FileInputList -
2015/04/17 16:08:58 - FileInputList - at org.pentaho.di.core.vfs.KettleVFS.getFileObject(KettleVFS.java:154)
2015/04/17 16:08:58 - FileInputList - at org.pentaho.di.core.vfs.KettleVFS.getFileObject(KettleVFS.java:102)
2015/04/17 16:08:58 - FileInputList - at org.pentaho.di.core.fileinput.FileInputList.createFileList(FileInputList.java:173)
2015/04/17 16:08:58 - FileInputList - at org.pentaho.di.trans.steps.getfilenames.GetFileNamesMeta.getFileList(GetFileNamesMeta.java:672)
2015/04/17 16:08:58 - FileInputList - at org.pentaho.di.trans.steps.getfilenames.GetFileNames.init(GetFileNames.java:315)
2015/04/17 16:08:58 - FileInputList - at org.pentaho.di.trans.step.StepInitThread.run(StepInitThread.java:69)
2015/04/17 16:08:58 - FileInputList - at java.lang.Thread.run(Thread.java:695)
2015/04/17 16:08:58 - Spoon - The transformation has finished!!

This is the most recent and thorough error I could produce.
I have the vfs.sftp.StrictHostKeyChecking.secure.mftexpress.com parameter defined in my kettle.properties file as well I have tried setting this parameter in the transformation parameters as well.
I'm on a mac (Yosemite 10.10.3) and PDI 5.3. I also get this error on my Windows 7 VM (parallels) running PDI 5.3. I also had this issue on PDI 5.2

Any thoughts/assistance is appreciated.