Cancellation of invoice receipt through MR8M

Hi experts,

We are trying to cancel the invoice documents which are created in 2006. While trying to cancel, we are getting the errors as below...

1. No reversal possible, reversal value must be reset. (This for one document)

2. Incoming invoice not allowed ORD 600015. (This is because, investment order is assigned in th PO of invoice.

So, please suggest me if any body has solution on it...

Thanks,

Satya