can't zoom mission map back out

After a battle at Jade Quarry ended, my mission map appeared at maximum zoom, and I can't figure out how to restore the default zoom level. I did a google search and discovered that this is a known bug. But the only solutions I found don't work for me because I only have a two-button mouse with neither a scroll wheel nor middle button emulation. (Windows XP Pro machine, default Windows mouse driver). Any ideas?

Thanks in advance for help.

UPDATE (WORKAROUND DISCOVERED): If I log out, log in/out with another account, and then log in again, then the mission map is back to normal. It also works to delete gw.dat, but that's more extreme.
FYI, regarding the support ticket, ANet had asked me to run the diagnostic program and send them results, and I never got around to that.
The bug still exists, and it happened for me many times in JQ, FA, and AB over the weekend.

Try going in to your options and setting a key binding to zoom in and out. Then click on the map and use the keys you just set up for zooming.

or

Try logging that character off and back on to see if the map will reset.

or

Buy a mouse with a wheel.

i would suggest buying a slightly higher quality mouse ;-)

Thanks for the suggestions.

Tried those already.

Actually I can probably borrow a mouse with a scroll wheel. I just don't want to have to switch to it every time I play in JQ and trigger the bug. I like my Kensington Orbit trackball, which is high-quality for me .

I also submitted a support ticket, and if Anet has a solution I'll post it here.

Found a workaround and updated original post.