This works around the problem on Linux, that the preferences window is too small in the French locale. The OK/Cancel buttons are not shown then.
make prefs window resizable
Have you tried a recent CVS HEAD version? We've recently reworked preferences to reduce the size of the window that reduces the required width quite a bit.
Thanks for the patch. This has now been fixed from 1.3.8 onwards. The preferences window was redesigned and the text should fit within 800 px width. If the text needs more horizontal space than is available it should wrap downwards with a vertical scrollbar if necessary.