If you go into the device manager does your computer has APM (Advance Power Management)? If it doesn't have this feature your computer will not be able to go into standby or hibernate. What I would recommend is downloading ThinkVantage System Update. This will search for all software associated with your make and model of laptop.
Run this and install the software it finds, reboot and see if you can get into standby mode.
Download System Update -
http://www-307.ibm.com/pc/support/site.wss/tvsu-update.htmlAlso take a look at this KB Artical for troubleshoot steps for standby and hibernate issues...
http://support.microsoft.com/kb/907477Hope this helps~!