Hi Cloughie,
I think I see the problem. There is a typo for the new line variable in the Export text dialog. It looks like you have a left square bracket instead of a left curly bracket. The Export text dialog's variable field will have the following variables : {fbas}{tab}{keyw}{nl}. The generated text file should have each line starting with the filename without the extension, then a tab spacing and then the keywords for that image. You should verify this before using it as a code replacement text file. In the IPTC Stationary Pad, you do not need to have the code replacement variable as part of the popup list. Just click the clear button at the bottom of the dialog to reset it and make sure the + box is not checked for the Keywords field. Now type \{fbas}\ in the Keywords field. Close the Stationary Pad to save the changes. Go to the Set Info Text dialog from the Edit menu -> Settings option and click the Reload All button to reload your updated code replacement text file. You can test the Apply Stationary Pad by selecting one image, right clicking the thumbnail and then click the Apply Stationary from the menu. Click the image's i button to verify it worked as expect. If so, then you are all set to update the rest of the images in a batch.
regards,
--Bob