It seems that the HD7 is the second next gen phone after the iPhone 4 to come packing with the infamous "Death Grip" Apparently holding your phone in the wrong way can lead to you losing your signals completely, HTC replied
"...it is inevitable that a phone's signal strength will weaken a little when covered in its entirety by a user's palm or fingers. We test all of our phones extensively and are confident that under normal circumstances reception strength and performance will be more than sufficient for the operation of the phone when network coverage is also adequate."
As you can see in the video the HD7 is indeed plagued with the death grip, but unlike the iPhone 4 people are saying that despite low signals the voice quality is good and they have yet to suffer call drops very frequently.
Source: WindowsPhoneThoughts
