Thanks, are you sure? I have 3 columns, not 4, at my frontpage showing the last 3 blog post preview images.
These images should be 290x130 px and so I have changed now in function.php (all heights to 130px):
/*preview images for special column sizes of the dynamic template. you can remove those if you dont use them, it will save performance while uploading images and will also save ftp storage*/
$avia_config['imgSize']['grid6'] = array('width'=>450, 'height'=>130); // half sized images when using 4 columns
$avia_config['imgSize']['grid8'] = array('width'=>610, 'height'=>130); // two/third image
$avia_config['imgSize']['grid9'] = array('width'=>690, 'height'=>130); // three/fourth image
Then I regenerated the thumbnails and reloaded my frontpage - it has no effect at all.
Or is it perhaps something of the others in functions.php?
//register additional image thumbnail sizes that should be generated when user uploads an image:
global $avia_config;
$avia_config['imgSize']['widget'] = array('width'=>36, 'height'=>36 ); // small preview pics eg sidebar news
$avia_config['imgSize']['related'] = array('width'=>130, 'height'=>130); // small images for related items (also for small blog overview images)
$avia_config['imgSize']['portfolio4'] = array('width'=>210, 'height'=>160); // small preview pic for default portfolio (4 columns )
$avia_config['imgSize']['portfolio3'] = array('width'=>290, 'height'=>200); // medium preview pic for 3 column portfolio
$avia_config['imgSize']['portfolio3_sb']= array('width'=>183, 'height'=>160); // medium preview pic for 3 column portfolio with sidebar
$avia_config['imgSize']['portfolio2'] = array('width'=>450, 'height'=>300); // medium preview pic for 2 column portfolio and small 3d slider
$avia_config['imgSize']['page'] = array('width'=>610, 'height'=>255); // image for pages and one column portfolio
$avia_config['imgSize']['blog'] = array('width'=>450, 'height'=>255); // image for blog posts (big)
$avia_config['imgSize']['featured'] = array('width'=>930, 'height'=>370); // big images for fullsize pages and fullsize 2D & 3D slider
$avia_config['imgSize']['fullsize'] = array('width'=>930, 'height'=>523); // big images for single portfolio pages
$avia_config['imgSize']['aviacordion'] = array('width'=>610, 'height'=>370); // big Image for aviacordion
Create a new thread and tell me what problems you are encountering and what you want to know. 
There is no step 3 :) 
