Version:            (using Devel)
Installed from:    Compiled sources
OS:                Linux

I have 2 screens (1680X1050 and 1280X1024).  As of recently the panel has changed so that the panel on the left screen appears as only 1280 wide instead if 1680.  Here is the panel output when starting plasma (with no config file).

plasma(22846)/libplasma Plasma::Corona::loadDefaultSetup: number of screens is 2
plasma(22846)/libplasma Plasma::Corona::loadDefaultSetup:      screen  0 geometry is QRect(1680,0 1280x1024)
plasma(22846)/libplasma Plasma::Corona::loadDefaultSetup:      screen  1 geometry is QRect(0,0 1680x1050)
plasma(22846) Panel::updateBorders: no location!?
plasma(22846) PlasmaApp::createPanels: Containment name: "Desktop" | type 0 | screen: 0 | geometry: QRectF(1680,0 1280x1024) | zValue: 0
plasma(22846) PlasmaApp::createPanels: Containment name: "Desktop" | type 0 | screen: 1 | geometry: QRectF(0,0 1680x1050) | zValue: 0
plasma(22846) PlasmaApp::createPanels: Containment name: "Panel" | type 1 | screen: 1 | geometry: QRectF(0,0 1280x56) | zValue: 150
plasma(22846) PlasmaApp::createPanels: we have a panel!
plasma(22846) PanelView::updatePanelGeometry: New panel geometry is QRectF(0,0 1280x56)
plasma(22846) PanelView::updatePanelGeometry: PanelView(0x95f320) thinks its panel is at  QRect(0,994 1280x56)
plasma(22846) PanelView::PanelView: Panel geometry is QRectF(0,0 1280x56)