Fine Uploader only works for a single batch of files

Fine Uploader only works for a single batch of files

My Fine Uploader implementation - using the core mode and jQuery - works
fine until I try to upload a second batch of files.
When the first batch of files have been uploaded (successfully), I can
click the button to add files and get the dialog to select files. However,
after I confirm the file(s) selection nothing happens.
This bit of code in the complete handler is causing the trouble:
$('#attachments-upload').button('reset'); // Bootstrap stateful button
#attachments-upload is the id of the button which is set as the button:
option as well:
$('#attachments-list').fineUploader({
uploaderType: 'basic',
button: $(#attachments-upload),
[...]
What's the issue here?