First of all, PPV can stand for Plum pox or Porcine parvovirus, I suspect you are talking about the later.
Not familiar with viral expression, but RNA of this gene should be the same as the single stranded DNA, but since you didn't do any RT, it wouldn't amplify. Only thing it can do is inhibit the reaction in the excess.
Since as I said I have no idea about this virus life cycle, it's maybe possible that the DNA undergoes some editing. Or what you see is unspecific product. If you can't get rid of it, you can try to sequence it to see what it really is.
Also Pfu is proof-reading but less eficient polymerase, you may try to amplify it with some other to see if your product is more distinct. For cloning/sequencing you can use a mix of proofredaing and normal polymerase.
And no, ssDNA can't have a product of half a length. In PCR all products become double-stranded anyway.