I have the latest Portfolio Performance 0.64.4, on a Mac.
From the all Securities -screen, I enter a new Transaction for a security: Delivery (Inbound).
The currency is EUR. I enter the quote for the stock as 1,788 (plus fees 5 eur + taxes 6 eur).
I press Save.
Now, when re-open the transaction (by right-clicking and choosing Edit) the quote has changed into 1,78799762.
This happens again if I try to change it into 1,788 - after saving and re-opening it is back in 1,78799762