Hi there,
I had the same problem, but this little tip here seems to have fixed the problem.
You need to download the BIOS Setup Utility from Compaq (You'll find it on the hp/compaq-site) and do the following:
In System Features - System Management disable ACPI. IMO ACPI only causes problems. With ACPI deactivated even APM suspend to RAM works (more or less).
yours,
Trond