I noticed that saving a pdf as a new file name returns a corrupt pdf file.
After digging into the code, I found that it's related to the GetFileStream() method od the PDFDoc class in pdf.cs
currentFileStream = new FileStream(WriterPDF, FileMode.Create, FileAccess.ReadWrite);
currentFileStream = new FileStream(WriterPDF, FileMode.OpenOrCreate, FileAccess.ReadWrite);
now it works as expected.
Also, there's also a problem in the CleanUp() (called while using PDFDoc Dispose), but I didn't got the time to check the cause of it (probably related to an open filestream or file still in use preventing the currentjobFolder to be deleted properly)