Problems appear to be afoot with Acer's recently announced Aspire X1200 HTPC. Several users are complaining that their network cards would go into sleep mode and then refuse to wake up without a restart; when told by Acer's tech support team to update the BIOS, the network issue is resolved but the HDMI output no longer works.
Obviously in an HTPC, not having a functional HDMI port puts a serious dampener on multimedia aspirations. Acer's advice so far has been for affected users to send their machines in to the Texas support facility, but of course there's no promise that they won't wipe all your data in attempting to fix it.
Unofficially, users are left with a choice of having a working HDMI output but intermittent network connectivity (or fitting a separate network card), or updating the BIOS and losing HDMI functionality. We're waiting for Acer to get back to us with an official response.
Update 08/27/08: Acer have been in touch with news of a hotfix; find out more here.