Updated from 3:13 p.m. EDTFrustrated by the lackluster performance of shares of Sun Microsystems ( SUNW), investors on Thursday called for reforms at the Santa Clara, Calif., company. But despite the proxy-based protest, it's unclear whether Sun will take the matter to heart. Gathered at Sun's headquarters for its annual shareholder meeting, investors overwhelmingly approved a measure to do away with the company's poison-pill provisions, and showed strong support for a measure to tie senior management's compensation to performance targets. In a preliminary vote tally, Sun reported that 84% of voters endorsed a proposal to give shareholders a greater say in the company's poison-pill provision, which is a method of fending off an unwanted takeover by instantly creating shares, thus driving up the acquisition price. The poison-pill proposal, submitted by William Steiner, an individual shareholder, calls for Sun to eliminate the provision or put it up to a shareholder vote. A second shareholder initiative, calling for linking senior executives' stock option grants to performance metrics, garnered 42.8% of the vote. A Sun spokesperson said the company's board will take the results of the poison-pill vote into account as it strives to maximize shareholder value. And Sun will continue to review all aspects of executive compensation to ensure that it is appropriately linked to performance and competitive market level, the spokesperson said. According to Teresa Johnson, a partner at San Francisco law firm Howard Rice Nemerovski Canday Falk & Rabkin, companies face a tough choice when shareholders rock the vote, as occurred with Sun's poison-pill provision. "It can be a difficult position for the company, because that is clearly a very strong message from the shareholders about their views," said Johnson. But she noted that changes to poison pills are "huge decisions," requiring the board to consider numerous factors in addition to shareholder desire. Sun is among many tech companies, including Apple ( AAPL)and Dell ( DELL), that have faced similar shareholder initiatives in recent years. But given that shareholder proposals are nonbinding, they're often nothing more than strongly worded messages.