Its not too good to bump that old thread, but this problem makes me crazy and today I finally found a sollution, hope this will helps to other people with same problem.
This thing happens in my case on slackware 12.1 and slackware 13.0 x86_64 .
Its almost the same as that that f000l says, but in my case setting
in .vimrc solved issue, with set mouse=a
problem still exists.