Activity Slip (Job) reports - Job Name & Number not appearing.

I need to produce a report showing the hours worked on activities per job so I've set up 2 test activities - "O' and "W" and created/processed timesheets with these allocated against the job numbers.

I produced the "Activity Slip [Job Summary]" and once I ticked the Subtotal by Activity box the report came up with all the info I needed execpt it doesn't show the Job Name or Number (the info is grouped in jobs though) - 

HOWEVER (and this is the interesting part) if I hover the mouse over the report where the name and number should appear, I get the "click on me hand" and if I click when the hand appears it takes me to the job card.  So the link is there but the words aren't (very strange).

I tried exporting the report to excell but it doesn't show the job name or number either.

Can anyone help me with this please?

I've attached a copy of the report - the job name and number should appear above the O & W of each section and the number should appear in the job no. column on the right.