I recently obtained a copy of the original broadcast of the pilot episode and noticed a difference between it and both the syndicated and DVD versions. The latter two versions don't have the stylized "Newhart" logo at the beginning of the opening credits... it's in a simple block font instead. However, the original broadcast has the regular logo that was used for the rest of the series. It also runs slightly shorter than the DVD version.

Interesting. They must have decided to make a change about the logo after they filmed the original.