SchnapperPro usually recognizes all sites delivered by eBay during a bidding process.
It may however happen that message samples expected by SchnapperPro can't be found due to changes made by eBay.
It is therefore quite possible that your bid was placed successfully while the status delivered by eBay could not be identified.
There even might have occurred an error during the bidding process for which there is no status message available yet.
In every case you should first of all open the item site to check if your bid has been placed.
SchnapperPro stores the details for every bidding process in a log file. Open the log file by clicking F8 and look for recent entries on the very bottom.
There you will also find the files to which SchnapperPro saved the unexpected server responses.
Log entries and server responses are important information to spot the source of an error quickly and -if necessary- make any adjustments in SchnapperPro.