Anybody experienced thumbnails not showing in TinyMCE 2.4.2 image selector?

[eluminous]

I am using CMSms 1.2.5 with Tiny 2.4.2 which was upgraded from the default Tiny that was installed by default. I am trying to work out why the thumbnail versions of an uploaded image are not showing in the image selection popup. Have checked to see that the thumbs are created correctly on upload and they are definitely there. Have checked all setting in the advanced and settings tabs and experimented with changing umask from 022 to 002. No luck unfortunately.

Has anybody been through this and found any happy outcomes?

[Dr.CSS]

Have checked this drop down?...

Filepicker style:

[eluminous]

Yes. Set to both filenames and thumbs. Selected all options in the filepicker style and updated many times to see if it would trigger anything. No changes...

[Deblus]

If the uploaded images are too big then I don't believe the thumbnails will generate

[eluminous]

all thumbnails are generated correctly and are sitting in the images folder. 

[Dr.CSS]

What is the permissions on the modules folder?... 777, 775, 755  try all...