I started using Mathematica 9 on Ubuntu 12.10 and, sometimes, autocomplete doesn't work. The suggestions window shows up for just a fraction of second, and quickly disappears.
Do you have any idea on how I can sold this problem?
Thanks in advance!
This problem is fixed in the newest version of Mathematica 9.0.1 (at least for me). Notice: Wolfram published several versions with the name "9.0.1" for Linux and only the current one (md5 sum 7fcbc4d1488757b10ef07740ac30a580) fixed this bug.
"ReleaseID" /. SystemInformation["FrontEnd"]
gives "9.0.1.0 (4092720, 4092443)"? If not, re-download Mathematica from the user portal and re-install it (or bug your sysadmin ...) $\endgroup$