When the taskbar is set to autohide, the area where the cursor must be positioned to get the taskbar to appear is not the most extreme position on the screen, but rather a small range several pixels in from the extreme. The means the cursor must be precisely postioned, which makes the gesture not as instant as I would like. BTW, I like xfce very much and have been very impressed with overall quality and utility I was an fvwm user for many years, then KDE for a while, but xfce was like a breath of fresh air. The installer is a particularly nice touch.
I presume you have the option set in the window manager to change workspaces when the mouse reaches the edge of the screen. This is not compatible with the panel autohide option, I'm afraid. Closing this as WONTFIX, please reopen when the cause is something else.
You are quire correct that I had the option set in the window manager to change workspaces when the mouse reaches the edge of the screen. Turning that option off "fixed" the issue with where the cursor must be positioned to pop up the taskbar. What doesn't make any sense is that with the option set in the window manager to change workspaces when the mouse reaches the edge of the screen, moving the cursor to the bottom of the screen, where my taskbar is, does nothing. Only the side are used for screen switching. So why can't I have both: screen switching and easy taskbar popup?
recently the ability was added to have a 2D workspace layout, so, if that's set up, you can wrap to other workspaces by going off the top or bottom of the screen.
The availability of 2D workspace layout would explain my prior lament. But I'm not seeing anywhere to set 2D workspace layout (in 4.2RC1). Is that in CVS only? If 2D is not set (and I like a horizontal layout, myself), should the bottom border be available for taskbar popup? Is this too trivial a quibble?
That's driven by the pager geometry. Set the panel vertically and the workspaces are laid out vertically, use a 2x2 pager and the worskapces are laid out 2x2, etc.