direct database manipulation will normally not show up.
Liferay service builder implements caching on entities (check the attribute in service.xml, if not specifically disabled the entities are cached).
Counts are not cached, but individual entities are.
If you used your SB code to update the entity, the correct value would be displayed.
I question your use of portlet preferences as the mechanism for passing the value around; if it's already in the database, why make it also a portlet preference?
