Fault : 2 questions about catalogue

[Stevo]

I put a question also in the dutch part of this forum, but will also try to write in English

http://www.prestashop.com/forums/viewthread/59476/installatie___configuratie/fout__2_vragen_ivm_gebruikersfouten_binnen_catalogus


I have 2 faults in my catalogue.

1) When I want to upload a picture, I have follow error "This is no GIF file, convert instead of rename" but I see later that picture got uploaded

2) I can't change positions of articles.

I'm using PS Version 1.2.5.0


Best regards, Steven