Poor image quality

I’ve added this on the Google Groups but not sure where the best place is to add support requested – here or google groups?

I have an image pane where I’ve added q=100 so that the quality should be the same as the uploaded image but it’s not – I cannot get the same quality image appearing on the site as that that I’ve uploaded.

I’ve even changed the code from

<?php echo get_image('slider-img'); ?>

to

<?php echo get_image('slider-img',1,1,1,NULL,'q=100'); ?>

If I view the image in the WP Admin post then that image is okay – it’s when it caches the image that the poor quality appears.

Really need to get this resolved as soon as possible as it’s on the homepage of a development site.

Thanks in advance for any help or advice on this issue.