Two operational managers at the division have been dismissed but are not being named for legal reasons. They left in the "last 10 days".
A brief statement by the company said the "division's management accounts do not reflect accurately its performance". A review of the breaches and internal controls is being conducted internally and with the assistance of auditors Deloitte & Touche.
Analysts had predicted a rise in profits to pounds 7m, but now expect the full-year result to remain unchanged at pounds 5.9m.
The company said the rest of its activities, particularly within the continental European computer division and the security print division, had performed in line with or ahead of expectations.
Kalamazoo said it would declare a final dividend not less than the 1996 final payout of 3.05p a share when preliminary results are announced around 26 June.