Unfortunately i'm facing the same issue. Phantom Keys while scrolling in XBMC. I tried the latest RC4 Release, installed MediaPortal to see if it's aXBMC issue (it's not, same issue on MediaPortal), tried to place Flirc behind a dimmed glas, tried several remote controls, modified any setting in the GUI. No success at all.
In the meantime i upgraded from Win 7 x64 to Win 8 for troubleshooting, but still no success.
Any helpfull hint ?