I'm using Xubuntu 8.04 (Hardy Heron) with Mousepad 0.2.13 (not listed in above versions?).
My problem with Mousepad is that the text search function by default has the "Match case" flag set. This is contrary to normal behaviour in other (GUI) editors. Please change this so that by default this flag is not set and therefore searches are done for any mix of case. Most searches in my opinion are for terms where the user is not sure about case anyway. Also most people have their keyboard set to lowercase when entering text. It is a pain having to uncheck this box every time I want to search.