Thank you for your post.
Since this used to work fine, something has obviously changed. The question is "What has changed?"
Let's handle the FileMaker side of things. First, create a new database file with one field and one record. Make it available through Instant Web Publishing and see if it hangs. If so, then something is wrong with either the web publishing engine or FileMaker Pro. I would advise uninstalling and reinstalling FileMaker Pro.
If web publishing with the new file doesn't hang, then duplicate the record 160 more times and see if it hangs with Instant Web Publishing. If this works, import one field from the records from the other table. See if that slows down.
If the hanging only occurs with this one table, then perhaps the layout or table is corrupt. Create a new table, make a layout similar to your old layout, and import the records. Does the problem continue to occur?
Please keep me updated on your progress.
Thanks for the quick answer, it gave me some ideas how to proceed to identify the problem.
As the web publishing part worked with any other views (and this is a rather complet setup), I checked when the last records were added by an online user. By deleting these records, the problem was not solved.
However, when I got back the file through Time Machine (thanks, Apple :) from one day before the last "online" record was added, it turned out to work fine, so it was the database that became corrupted sometimes when adding those records.
The strange thing is, the file continued to work fine locally, there was no problem at all - I also found a recovery log, so FM tried to fix the file, but somehow this did not help the IWP, only enabled local work.