Inconsistency in data signs

Hello experts,

We've experienced a strange issue. Almost all data in two of our models have switched signs since this morning. No modifications have been made in acctype property, no scripts or BADI's have been executed since last week and in general no modifications have been made in the configuration.

Could this be a consecuence of a SP installation or other update done at the server level?

I do appreciate your comments.

Regards,

Nidia Olguín