Plaintree Systems (PTEEF) 20-F/A 2007 FY Annual report (foreign) (amended)

Exhibit 4.5

Certification Pursuant to

18 U.S.C. Section 1350,

as Adopted Pursuant to

Section 906 of the Sarbanes-Oxley Act of 2002

In connection with the Annual Report of Plaintree Systems Inc. (the “Company”) on Form 20-F for the period ending March 31, 2007, as filed with the Securities and Exchange Commission on the date hereof (the “Report”), the undersigned hereby certifies that to the best of his knowledge:

1.

The Report fully complies with the requirements of Section 13(a) or 15(d) of the Securities Exchange Act of 1934; and

2.

The information contained in the Report fairly presents, in all material respects, the financial condition and results of operations of the Company.

Date: October 10, 2007

Per:

 

Name: David Watson

Title: President,Chief Executive Officer and Chief Financial Officer

The foregoing certifications are being furnished solely pursuant to Rule 13a-14(b) under the Securities Exchange Act of 1934, as amended, and 18 U.S.C. § 1350 and will not be deemed “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended, or otherwise subject to the liability of that section. Such certifications will not be deemed to be incorporated by reference into any filing under the Securities Act of 1933, as amended, or the Securities Exchange Act of 1934, as amended, except to the extent that the Company specifically incorporates them by reference.