I've noticed that the way you've set the tech tree to sort the available techs to research doesn't get remembered when the screen pops up asking for the next tech to research.
For example, say you select to sort the techs by catagory when asked to select a tech, when that tech has finished, the techs will be sorted as they were when you start a new game, but it'll still say that the techs are sorted by catagory. It's easy to sort out, simply switch to a differant way of sorting, then switch back to catagory, but it's annoying to keep having to do this.
[/edit] this shoulda been posted in the bug reports section, no idea why it wasn't.