Hello everybody, I have extensively googled for this one but have not found an answer so I thought I'd post a message here maybe somebody will now the answer. I have a compaq presario 2500 laptop and had installed RedHat9 for some years. ACPI used to work just fine from the start. I upgraded to FC2 a year ago or so and still no problem. Eventually I was running a custom kernel that had APM disabled and ACPI enabled. Recently I upgraded to kernel 2.6.10-1.771_FC2.stk16 coming from Linuxant because I wanted the newest version of ndiswrapper to run my wireless card. That's when the funny ACPI behavior started. Notice that they claim this is an identical kernel to the official release besides the stack sizes changed to 16k instead of 8k, so that all wireless drivers can run with no problem. Of course the ACPI problems persist even without the ndiswrapper driver loaded. So what is the ACPI behavior? For example, I try to change the brightness but it does not change concurrently. I have to press the button combination a few times only for the previous presses to take effect. Also, the battery state is not updated unless I initiate some specific event, like changing the monitor brightness. ACPI with this kernel had some irq conflicts so I had to pass the 'acpi=noirq' option to the kernel. The problem persists though. Any good ideas? Thanks, Filippos