By default SXEmacs pastes X selections where the mouse pointer is. How do I disable this?
Examine the function
mouse-yank, by typing C-h f mouse-yank
To get SXEmacs to paste at the text cursor, add this your init.el:
(setq mouse-yank-at-point t)
You can also change this with Customize. Select from the
(Customize)->Emacs->Editing->Mouse->Yank At Point... or type M-x
customize RET mouse RET.