Nope, it's a design flaw.
Apple are giving out free bumpers or cases, but these make your iPhone 4 look cack.
I personally have just stuck a piece of Sellotape/Sticky-Back-Plastic over the bottom left corner of my iPhone 4.
Careful, you might set off the non-issue Apple heroes
![Frown :( :(](/styles/default/xenforo/vbSmilies/Normal/frown.gif)
I personally use my phone on a good network and don't care about a single bar signal loss.
This is also a stupid point to make, I shouldn't need to explain why (again).