I have found a problem in W7 and Kubuntu using Chrome (don't know about Firefox because I have not had time to try). I have many examples of 74HC and HEF4000 parts that work OK but the examples of the logic primitives need the symbols updating to get the GND/VDD connections to work properly. The problem I have found is that if I select a logic primitive symbol from My Parts or EasyEDA Libs in Sandbox and try to place it on the schematic, the whole browser freezes (actually it runs very, very slowly) for some minutes. Chrome often gives a page crash message!