> What steps will reproduce the problem?

1. Unzip attachment and visit mouse-zoom-bug.html in IE 8 or 9.
2. Try to select an area. Note that nothing happens.
3. Comment out "grid: { backgroundColor: 'yellow' }" in file. Repeat test and note that it works properly (selection area appears).
4. Try above tests on Firefox 16 and note that it works properly in all cases.

> What version of the product are you using? On what operating system?

Flotr 0.1.0alpha on Win7 & WinXP.

I debugged a bit and found that the mousedown event wasn't firing at all when the grid is colored.

I accidentally reported this against Flotr 0.1.0alpha, but the bug is present in 0.2.0alpha as well.