Memo field not updating

Start by looking at your data - to which we have no access - and check that an entry exists with an ID of "29". If no rows have that value, no rows will be updated.
Then look at your code to use that UPDATE command, and check the return value when you execute the SQL command - it should be the number of rows updated. If that isn't zero, then Access thinks it has updated some rows, so you need to check that you have the right DB, right table, and right data.

We can't do any of that for you: we don't have access to your code or your DB.