Progress bar while downloading a map

```
What steps will reproduce the problem?
 1. Press Download button
 2. Change zoom min to -2 and zoom max to 5
 3. Press Download button
 4. Progress bar percents are changing not correctly. Begin with 80% and decrease, then increase, and then decrease again.

Version is 0.7.5.0. Windows 7 64 bit.
```

Original issue reported on code.google.com by `nov...@gmail.com` on 23 Nov 2010 at 2:33
