What Happened and How Do I Avoid It?

this keeps happening to me. i'm building something and i have my view zoomed way in. i click a prim's arrows, usually close to the build tool. the view suddenly shifts slightly and the prim is gone.

i've searched around, followed each axis out away from my object, done Hilight Transparent and such and i've never found one of these prims again. i don't click the building tool, only near it, and i'm not changing the numbers when this happens, just clicking the arrows like i'm going to drag the prim.

what's going on here, how do i avoid it, and any suggestions for finding these prims? are they lost forever?

It could be that you dragged items underground by mistake.

To retrive items from underground, here is a nice tutorial: http://www.sluniverse.com/kb/article.aspx?id=10052

i'm 600 meters up. good tip for next time though. thanks.

Its a bug.
The lindens know about it.
We have lost entire buildings to it. ugh.

fen-

I've found that at certain angles, especially head-on, clicking the arrows over amplifies the amount of prim movement you intend. Like if you're looking along the x-axis, you can use the y and z arrows, but if you accidentally click that red x arrow, the prim shoots away on the x-axis. If you know about where you are in the sim, you can type a value into the x-axis window to get it back... unless it crosses a sim border.

Because of this, I always rotate the camera perpendicular as possible to the axis I want to drag along.