2824 Switch Locking up

[Printer_Al]

I have a 3Com 2824/3C16479 switch that has performed reliably for 3 years. This is a 24 port unmanaged switch. After all the computers have been shut down overnight, it always took a minute or so to rebuild the routing tables when we returned. Usually, I could open a browser momentarily, X out of the browser, then re-try. The system would always respond favorably. Recently, it seems to lock up after a period of non-use overnight or over the weekend. I can unplug the switch momemtarily, plug it back in and it immediately resets itself and operates normally. Has anyone experienced this? Is there a firmware upgrade for this switch? If anyone has the firmware upgrade, can you send it to me or send me a link to a download site? Could this be related to an aging router?Many thanks for your help. Al