The TB report uses the stored figures displayed on a nominal record Details tab.

Either these figures are corrupted, or when you look at the nominal activity you are not looking at the correct different date range - this latter is the more likely (it is easy to change it for a specific purpose (or accidently)  and it doesn't automagically reset to all); check the 

• Show: [             ]
• Date: [                           ]
• Type: [              ]
• O/S Only [  ]
• Trans.: [                  ]

boxes are displaying the data you expect.  Normally, for all transactions it would be something like:

• Show:  [Custom range...]
• Date: [01/01/1980 to 31/12/2099]
• Type: [All]
• O/S only [  ]
• Trans.:[1 to <your last tran>]