Dell Inspiron 1545 Power Issues

I got this Inspriron 1545 running on Window 7 Ultimate.  My concern is it used to say plugged in not charging but now it doesn't even recognize that the unit is in fact plugged in.  I have tried flashing the bios to the latest (A14) prior to my laptop not recognizing the power cord but still said plugged it not charging.  Today I removed the battery and waited a couple of minutes then snap it back in and since then my laptop now thinks it running only on battery and not plugged in.  The odd thing is the my laptop still runs with the battery out.  Soon as I pop it back in then it thinks its not plugged in.  Can anybody help.  I'm down to 7 percent on battery life although that doesn't matter if my unit runs without the battery.  I do have a replacement battery (New 9 Cell) but even with the new battery it still doesn't recognize that it is plugged in.