I had exactly the same experience as the people above. I also called Krakow airport and they are very frustrated as they said the deer thing was a once off incident. They also said that Ryanair hadn't been in contact with them.
I also sent an email to Krakow Info online to see if they knew what the issue was and this is the reply that I received:
From: Krakow Info [mailto:krakow-info@krakow-info.com] Sent: 24 February 2007 13:14
Hello
Thank you for your interest in our service. Your questions were:
“(1) I received the below communication from my airline this morning. I accepted the changes to my flight but they are very inconvenient. Can you tell me if Krakow Airport is working to try to solve the problem with the deer inside the airport fences?
(2) Also, when do you expect for night time flight to be going again to Krakow airport?”
Answers.
(1) Actually, the deer live outside the airport fences and the airport’s management has been paying attention. They say they have managed to remove most of the animals from the nearby forests. It’s matter of opinion whether they really do their best and if that’s enough to solve the problem.
(2) Please ask Ryanair. As far as I know other carriers fly to Krakow as usual, British Airway and Lufthansa in that number.
Yours truly Krakow Info
PS The “Questions Answered” service is available solely through the Krakow Info site. In case of further queries please use again the page
www.krakow-info.com/quests.htm