Comment 6 for bug 229936

Nuisance partly solved when resuming from SUSPEND (I did not try hibernation yet). Hardware: HP 2510p laptop.
Go to menu System --> Preferences --> Power Management
Tab: General, uncheck (at bottom) "Use sound to notify in event of an error"

The beeping nuisance occurred on my laptop as a result of upgrading from gutsy to hardy so the beeping probably is a hardy bug. The fact that Ubuntu detects an error might be an older problem. What surprises me is that a few suspend-related messages are written to /var/log/messages only when the laptop resumes ("suspending consoles", "ACPI: PCI interrupt", "Stopping disk", "ricoh-mmc: Suspending").

The hint for turning off the beeping was found here (tamias' 11:53 AM post):
http://ubuntuforums.org/archive/index.php/t-766402.html
[SOLVED] DPMS issues with suspend and laptop lid