Comment 1 for bug 135658

This happens in Ubuntu 7.10 (AMD64) as well, and is not limited only to Synergy on Windows machines -- all connected clients do not work if the machine running the synergy server is also running Glipper.

There are no issues if you run Glipper and then run Synergy in client mode as long as the server is not running Glipper.

No idea what causes this, but my "workaround" is to run Klipper instead of Glipper on the server; it's not GTK, but they work the same way, and it does not conflict with Synergy.