My check register ending balance and the assett account on the balance sheet do not match...  
Any suggestions?

The check register is correct (GL-I) and the balance sheet is wrong (GL-F).  Thanks ~S~

If everything is posted in GL-O and they still do not match and the check register is correct, use GL-B and make a type 1 General Journal entry to correct the balance.  This will hit the GL Balance but not the check register.  The tricky part, of course, is where to post the other side of the entry.  Cash is usually posted against AR or AP but if both those accounts are correct, you will need to put it someplace else.