I recently upgraded from the last stable release 2.4.20 to 2.5.28 & then to 2.5.29 in the last few days.
The improvements are dramatic: beautiful xft anti-aliased fonts, no more crashing of an xterm upon font scaling, less flicker, etc. However, I have, almost completely lost a functionality that existed in 2.4.20. In that version I could use the left mouse button/button 1 to highlight any text in any application (button down followed by motion), then switch to any other open application & upon clicking the middle mouse button/button 2 paste the selected contents into that running process. It has worked flawlessly for years. Now, with 2.2.28|29, NONE of that works. In fact, within gvim on a single buffer edit, I can NOT use the mouse to highlight & paste. I can no longer copy & paste from an xterm|gvim|xpdf to a firefox entry box. I have tried rebuilding 2.5.28&29 with many different configurations (even using libstrokes, gtk), but, every attempt failed to cure the problem. I have carefully perused all the build logs & there are NO indicated errors, missing libraries, etc. Thanks for the attention. PS I am on a very current Linux system.