Symptoms

SQL table SmartObject contains numbers in certain column, numbers entered correctly and displayed as expected in SQL Server Management Studio, but Tester Tool and List View return these numbers with 9 additional zeroes added to the end (as if original number multiplied by 1.000.000.000).
 

Diagnoses

This issue occurs in distributed environments when there is a mismatch in terms of Regional settings configured on K2 server and SQL server (for example one of them has German settings while another English). When configuring the servers for DateTime cultures in K2 smartforms, it is important to ensure that all servers are using the same time zone and culture settings.
Distributed environments have to be configured as described in the following KB article:
Configuration settings required when configuring the servers for DateTime cultures
http://help.k2.com/kb001458
 

Resolution

Configured regional settings across the environment along with SmartForms execution culture as described in this KB:
http://help.k2.com/kb001458
Client confirmed that it resolved the issue.