After working with Caspio Support I recommend the following change be made to the SOAP API "handbook". In section 3.3.28 UploadFile the VB example incorrectly states the final command with parentheses.
It currently reads: aobjWS.UploadFile(strAccountID, strProfileName, strPassword, "file.txt", fileContent, "text/plain", -1, false)
It should instead read: aobjWS.UploadFile strAccountID, strProfileName, strPassword, "file.txt", fileContent, "text/plain", -1, false
I believe the handbook should be revised accordingly.