The KDE shortcut for Find Again/Find Next is F3, and it's also the shortcut in many Windows programs and cross-platform programs like Firefox. LO Calc doesn't seem to assign F3 to anything else, so this seems needless inconsistency.
Steps to reproduce:
1. Bring up LO Calc
2. Ctrl-F to search for something.
3. Press F3.
Pressing F3 should perform Find Next, or as LO calls it "Repeat Search".
I see Writer assigns F3 to "Run Autotext Entry", so maybe only assign F3 in LO programs that don't assign it elsewhere.
To fix this I went in to Tools > Customize > Keyboard > LibreOffice and added F3 as Edit > Repeat Search. But it didn't take in Calc, I had to add it in Tools > Customize > Keyboard > Calc.
According to http://en.wikipedia.org/wiki/Table_of_keyboard_shortcuts , Gnome's shortcut for Go to next search result is Ctrl+G, so maybe also add that as another shortcut, though it's often used as a "Go to (page/whatever)" shortcut.
Platform (if different from the browser): Kubuntu 12.04 alpha 2 amd64 with regular updates
Browser: Mozilla/5.0 (X11; Linux x86_64; rv:11.0) Gecko/20120216 Firefox/11.0 SeaMonkey/2.8
This is already implemented by Jan Holesovsky: http://cgit.freedesktop.org/libreoffice/core/commit/?id=c6ec7ed43b0861e1c96d62aa75b594b1dd81e315
It will be available in LibreOffice 3.6.0, at least.
Note that *currently*:
* it can be used only when the cursor is in the findbar
* we also have Ctrl+G to do this (bug 46438)
* it is hardcoded, so it isn't configure-able
More info: http://nabble.documentfoundation.org/Libreoffice-ux-advise-Find-Next-Find-Previous-context-shortcut-keys-show-or-not-td3973838.html