[fallen1]

The BIOS update might fix your problem..then again, it might not. If the problem is that your current BIOS has become somewhat corrupted and/or unstable, that could cause your motherboard to not recognize the slot correctly or to mismanage the voltage going to that slot. In that case, a BIOS update would almost certainly fix the problem (assuming that it didn't physically fry the slot with bad voltage). If the problem is that the slot is actually fried, then the only fix is a new motherboard. Always remember that just because it doesn't look like there's something physically wrong with it that doesn't mean it isn't fried. There could be broken pins or circuits inside the plastic slo housing, a bad voltage regulator, a faulty resistor, etc.
Updating the BIOS can't hurt, and even if it doesn't fix the problem you are having with the RAM slot it may let you squeeze a bit more performance out of your machine.