Seems Marius is right. I'm Norwegian too and this occurs on Synaptic 0.75.9ubuntu1 in Linux Mint 13 as well. Using sudo LANG=en_EN.utf8 synaptic works but is not very practical since the Package Manager entry in MintMenu is not editable, and also MintUpdate can not install updates because of this.
Seems Marius is right. I'm Norwegian too and this occurs on Synaptic 0.75.9ubuntu1 in Linux Mint 13 as well. Using sudo LANG=en_EN.utf8 synaptic works but is not very practical since the Package Manager entry in MintMenu is not editable, and also MintUpdate can not install updates because of this.