sleep and shut down works nicely.some months back hibernate also used to work with the same
software setup (windows 7 32 bit ultimate....,ATI radeon 7500...).
when i request hibernate it starts writing to harddisk ,
After some time it just whistles and restarts
Any suggestions,solutions....
My hardware is
T41 2374 7FU 1.5 GB 150GB ,1USB port not working,14 " lcd,6 cell

Several possible reasons:

• Incorrect driver, or incompatible driver update, particularly graphics adaptor - for the ATI7500, driver version 6.14.10.6606 is best.
• Power management of devices (particularly network adaptors), "allow this device to wake the computer" should be disabled (can cause computer to wake immediately after hibernating).
• All USB and peripheral devices must be disconnected! even an external VGA monitor can cause hibernation problems.
• Boot Configuration Data (BCD) problem, see this thread http://forum.thinkpads.com/viewtopic.php?f=45&t=89499 and this http://social.technet.microsoft.com/forums/en-US/itprovistasp/thread/4d74523f-2b9e-4fe7-9b5e-f0153166adcc/ (vista, but also relevant for Win7).
• If you have multiple OS on the computer, ensure the boot flag is on the same partition that Windows boots on (C: or the special small recovery partition) http://ubuntuforums.org/showthread.php?p=8940051

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On my T42, I had a similar problem, and had to go through all of the above to solve it. Hope it helps...