Antenna issues may not be such a surprise to Apple. A senior antenna expert at the technology company, who is hosting a press conference tomorrow to address complaints of bad reception, reportedly warned Apple chief Steve Jobs about these design flaws in an early phase of development.

Bloomberg.com spoke to people familiar with the matter. From the piece, “Last year, Ruben Caballero, a senior engineer and antenna expert, informed Apple’s management the device’s design may cause reception problems, said the person, who is not authorized to speak on Apple’s behalf and asked not to be identified. A carrier partner also raised concerns about the antenna before the device’s June 24 release, according to another person familiar with the situation.”

Two weeks ago, Apple tried to explain the issue in a letter to consumers. The letter claimed that the low bars was not an issue in the phone’s reception, but rather an issue of how the formula for how bars are calculated. The explanation was confusing, hopefully tomorrow’s press conference will have more details.