You could probably just remove the echo statement line for all but one of the plugins so that the style sheet isn't repeated. Either that or remove the repeated style sheet from the plugin pages and just add it to the main page itself.
Your friends over here at WebAssist! These Dreamweaver extensions will assist you in building unlimited, custom websites.
These out-of-the-box solutions provide you proven, tested applications that can be up and running now. Build a store, a gallery, or a web-based email solution.