I have a similar problem also.The icon disappeared from my panel even though network manager is still running. I sometimes have to connect to other networks if I am at someone else's home etc. This makes for a tedious process without the ease that that icon provided. I also have had a lot of problems with packages not being downloaded due to dependency issues or md5 sums not matching. I have been using Ubuntu since the 6.06 LTS release, and although this is not the first time I have encountered a shoddy release, for the first time I am considering switching to another distro. This release was certainly not stable enough to be released, and it is especially disturbing because this is a long-term support release. I am afraid that Ubuntu may be on its way to becoming the "Windows" of the Linux world.