The premium edition Player's Handbook (2012) includes stealth errata that changes the previous printing's sentence from, "Shields do not affect a character’s maximum Dexterity bonus," to—and I'm really not kidding here—the following: "Shields other than tower shields do not affect a character’s maximum Dexterity bonus" (123).
As it's the latest printing of the Player's Handbook, the premium edition takes precedence over previous printings, making it so that, yes, a tower shield—uniquely among the Player's Handbook's shields—has a Maximum Dex Bonus. (It's +2.) Thus the poor blighter using a tower shield must, in fact, contend with this.
"How does this change affect other shields?"
So far as this reader can tell, most of the game's other shields—including the exotic shields from Races of Stone—don't have a Maximum Dex Bonus, but the chitin tower shield (Races of the Dragon 121-2) (360 gp; 45 lbs.) and the steel tower shield (Races of Stone 158) (75 gp; 100 lbs.) do. (They're, respectively, +3 and +2.) However, as items named tower shields therefore presumably covered by the feat Tower Shield Proficiency (PH 101), these shields will also likely be equally impacted by the stealth errata from the premium edition Player's Handbook in all but the most rules-as-written of campaigns, forcing their users in most cases to also contend with those shields' Maximum Dex Bonuses.
The real outlying shield is the hide shield (Sandstorm 99) (50 gp; 30 lbs.) that's presumably covered by the feat Shield Proficiency (PH 100)—the text not noting otherwise, instead noting only that it can grant "cover as a tower shield does" and that it's "made of lighter material than a tower shield." Sandstorm's Table 4–2: Wasteland Armor says that the hide shield has a Maximum Dex Bonus entry of +4.
As the hide shield is not a tower shield—neither in name nor (apparently) by proficiency—, and there's no explicit exception to core rules made by Sandstorm for the hide shield, and there's no Sandstorm errata, the Maximum Dex Bonus for the hide shield could be construed as technically an error, the primary source (the Player's Handbook) superseding the secondary (Sandstorm), eliminating the hide shield's Maximum Dex Bonus. However, a case can also be made for Sandstorm itself as the primary source for the hide shield therefore that book's table overriding even the Player's Handbook text.
This reader suspects that a player trying to convince a DM to allow the player's Dex 30 rogue to realize her full Dexterity bonus to AC while she uses a hide shield will see the DM rule in favor of Sandstorm as the hide shield's primary source… but it couldn't hurt to ask.