A tip, that works better for me, when you want to report a bug report try to enumerate what you did in easy to reproduce step, so we can test for ourselves what happens. e.g.:

  1. go to edit http://openstreetmap.org/login?referer=%2Fedit%3Flat%3D59.334%26lon%3D18.0655%26zoom%3D14
  2. get a rotating wheel for 5 min
  3. go to http://openstreetmap.org/login?referer=%2Fedit%3Flat%3D59.334%26lon%3D18.0655%26zoom%3D17
  4. get a rotating wheel for 10 s
  5. zoom out three times (to the same as above)
  6. get a rotating wheel for 1 min

This is the way bugzilla tells you to do it and it works very well for firefox and such…

In this case your screen resolution, would probably be important as well, but if I tried to repete those steps I could more easily see what the problem was.