Exhibit 2.2 ESSI MEMORANDUM OF UNDERSTANDING --------------------------- TO: Michael F. Shanahan Sr. FROM: Gary C. Gerhardt RE: Employment Contract dated November 1, 2004 DATE: April 30, 2005 Mike: Reference is made to the Change in Control provision contained in paragraph 21 of your employment agreement dated November 1, 2004, a copy of which is attached. As you have stated, effective April 30, it is your intent to no longer be considered an employee of ESSI and, as a consequence, you would no longer be compensated if the Company were sold under the Change in Control provision of the employment agreement. Given the fact that you have been asked to explore the possible sale of the Company as your new role as a Consultant, we agree that you should be compensated for your efforts over and above the compensation specified in your Consulting Agreement dated May 1, 2005. Accordingly, this is to confirm that we have agreed to negotiate in good faith with you the amount of a reasonable "success fee" should there be a transaction which effectively results in the "Change in Control" of ESSI as that term is defined in your Employment Agreement of November 1, 2004. /s/ Gary C. Gerhardt ----------------------------------- Gary C. Gerhardt Vice Chairman Chief Financial Officer Acknowledged and approved as to both form and substance: /s/ S. Lee Kling /s Kenneth E. Lewi - --------------------------------------- ----------------------------------- S. Lee Kling Kenneth E. Lewi Presiding Independent Director Chairman Compensation Committee