sitemap error

I ran the script and I got this included w/ the result:

Warning: sleep() expects parameter 1 to be long, string given in /home/onlin19/public_html/forums/vbseo_sitemap/vbseo_sitemap_functions.php on line 614
[create sitemap file] filename: sitemap_2.xml.gz, number of urls: 50000 [17s (+7s)]
[create sitemap in text format] part #3 [17s (+0s)]

Warning: sleep() expects parameter 1 to be long, string given in /home/onlin19/public_html/forums/vbseo_sitemap/vbseo_sitemap_functions.php on line 614
[create sitemap file] filename: sitemap_3.xml.gz, number of urls: 50000 [23s (+6s)]
[create sitemap in text format] part #4 [23s (+0s)]

Warning: sleep() expects parameter 1 to be long, string given in /home/onlin19/public_html/forums/vbseo_sitemap/vbseo_sitemap_functions.php on line 614

What does that mean? How do I fix it?

This is not an error (just a warning message) and sitemap will still work correctly, but check your Sitemap Generator "Delay Execution" option - it should be a number.