I have Mozilla 0.8.1 running on one X server, which also runs x2x (version 1.27-5 from potato) with the command line "x2x -to 172.16.1.4:0 -resurface -east" to combine two displays. The latter is an NCD 19r X terminal running the default NCD X server software (X11R5 I believe). The former computer runs XFree86 4.0.1 on Debian GNU/Linux potato (Mozilla/5.0 (X11; U; Linux 2.2.17 i686; en-US; 0.8.1) Gecko/20010326). Whenever I select something (e.g. a URL) on the X terminal (on any application I have) and try to paste it in Mozilla running on my PC, it fails with no effect. Pasting into other programs (xterm, emacs) and then selecting there and pasting into mozilla works. I have experienced this with Mozilla 0.7, 0.8, 0.8.1. I have not tried it with any earlier versions or with any other remote X servers.

Looks like a duplicate of "Paste (using middle button) of clipboard contents that come from a remote window fails". Same symptoms.... *** This bug has been marked as a duplicate of 55312 ***