Hiya NaturalWriter,
I'm guessing the problem could be related to file sizes and uploads.. I've noticed that large file sizes can also cause problems with how galleries work with CMS's like Wordpress with some very strange displays.... and of course loading problems... I would look at your image sizes and if its more than 1Mb - seriously consider reducing that.... You can find some free utilities online which can help with that...
If that's not the problem - then perhaps you could have issues with bulk uploading... If so check out:
http://premium.wpmudev.org/blog/bulk-upload-files-to-wordpress-media-library-using-ftp/
Perhaps you have an issue with your allocation of PHP memory... For example that can happen when you have too many plugins installed... If so contact your web host to increase that....
Or perhaps the issue could do with permissions on your image folders, which prevents your CMS from reading them correctly... e.g. Folder permissions on Linux servers should be set to 755 e.g. if using Wordpress...
If you can provide a bit more information that will help with identifying the specific cause and hopefully solution... Hopefully one the of above suggestions helps! Let us know how you get on ;-)
Best of Luck,
Sid
