Thanks for posting.
I will need some more information regarding your setup and issue to help with your problem.
What is the exact behavior when double clicking the script button? Does it bring up any error messages?
What is the script doing in your database? Could you post a snippet of this script?
What version of FileMaker is the instant web publishing running through?
Is the database hosted from Macintosh or Windows? What are the system specifications of the host machine?
How many databases is this happening on?
Does the behavior happen for all users?
I would suggest creating a new database file and add the same script into the new file. Host this new file through Instant web publishing and test if the same behavior occurs.
I have the double click problem as well. It happens with certain scripts and is 100% reproducible.
Here an example: I have a layout with a portal showing some related records. In the line of the related records I have a button which performs only one scripts step "go to related record" (Show only related record, match current record only), nothing else, as simple as possible. Clicking once via IWP all runs fine. Double clicking really brings unpredictable results. Sometimes an error: "Record not found. The specified record was not found." Clicking on OK then FM jumps to the first of the related records. In other moments it occurs that the "Go to related record" just lands on another record (without error message) which is not related at all.
I can reproduce this in different layouts, the problem always occurs.
I tried a workaround: Instead of using "Go to related record" performing a find (Go to Layout …, enter find mode, set field with data to find, perform find), but the same problem happens.
IWP is running FM Server 11 Advanced on Mac OS 10.6.8 on Intel Core 2 Duo 2,0 Ghz and 8 GB RAM.
The behavior is happening on one database, as I have hosted only one on IWP I can't say much about another.