This week's GfK Chart-Track data, which includes the top 40 multiformat software charts, has been delayed today.
ELSPA's David Smith said: Unfortunately a major retailer has had system problems and as a result has not been able to deliver their Saturday sales data.
We understand that the problem will not be resolved until later today so it is likely that the charts will not be produced until late Monday or Tuesday morning.”
Last week Ubisoft's Just Dance reclaimed the UK top spot, knocking Just Cause 2 down one place ahead of EA's Battlefield: Bad Company 2.
On Friday 2K Games' Borderlands DLC add-on pack went on sale – the only new release to hit UK stores last week.