It certainly sounds like a server or PHP related issue although it seems strange that you are left with blank page (with no error messages) and a working gallery. It sounds like the script is stopping short of completing the import (perhaps due to a script timeout) and, although the gallery is created, the entry is not written to the page records.
Does it happen with every gallery you import?
How many images are in the gallery you are importing?
Try importing a small gallery (with just 2 or 3 images) to see if it happens with this.
If it seems to happen only with large galleries, then you could perhaps try increasing your PHP max_execution_time directive (for the set_time_limit() function) to see if this helps. The default value is 30 (seconds) but try a value such as 300 (which is what Showkase attempts to use internally for certain functions, such as publishing, if max_execution_time is set to a lower value in the PHP settings). Increasing the max_execution_time in your PHP settings might help.
You should be able to check your PHP settings using phpinfo() as follows:
Create a new file in a plain text editor with the following code: <?php phpinfo(); ?>
Save the file with a .php file extension (for example, 'phpinfo.php').
Upload the file to your web server and open it in a browser.
You should be able to change PHP values using a php.ini file, via an .htaccess file or via your web hosting online Control Panel.
If you have trouble changing any PHP values, your web host should be able to help you out.
Hopefully increasing max_execution_time will solve your problem.
However, if this does not help, then please let me know and I'll try to help further. Thank you.
Edit:
Incidentally, if you are not already using the latest version of Showkase, you might like to try upgrading to v1.6.1.
Instructions can be found on the Upgrading Showkase support page.