You may need to re-link the items in your project spreadsheet to the Catalogue. Try the following.
First select an item in the project spreadsheet by clicking on it.
Once selected press CTRL+A on your keyboard. This will select all the items in your spreadsheet.
Now right click on any of the selected items in the spreadsheet and select "More->Link To Catalogue" from the pop-up menu.
You may receive a message saying some items could not be linked. Click "OK" if this dialog appears.
Now that the items are linked right click on the selected items again. This time select "Update from Catalogue->SpecSheet"
That’s it. This should link all available cutsheets to the items within your project spreadsheet.