I was geting this annoying message and system was going into hibernate mode."The installed battery may not be properly connected to the computer or may not be compatible with the computer.Click "OK" to enter Hibernate mode,and remove and reinsert the battery. See the VAIO(R) User Guide for more information about using the battery."
I found this solution from Sony Support. Follow these steps to fix this problem.
NOTE: If prompted for an administrator password or a User Account Control prompt is displayed, type the appropriate password, click Continue or click Yes .