Hi,
try this:
In product_info.php:
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Find:
echo '<a rel="image_group" title="'.$title.'" href="' . ($m_source ? $m_source : DIR_WS_IMAGES . $product_info['products_image']) . '" alt="' . $product_info['products_name'] . '" target="_blank">' . tep_image(DIR_WS_IMAGES . $product_info['products_image'], $product_info['products_name'], SMALL_IMAGE_WIDTH, SMALL_IMAGE_HEIGHT, 'hspace="5" vspace="5"', false, 5) . '</a><br />';
And replace with:
echo '<a rel="image_group" title="'.$title.'" href="' . ($m_source ? $m_source : DIR_WS_IMAGES . $product_info['products_image']) . '" alt="' . $product_info['products_name'] . '" target="_blank">' . tep_image(DIR_WS_IMAGES . $product_info['products_image'], $product_info['products_name'], SMALL_IMAGE_WIDTH, SMALL_IMAGE_HEIGHT, 'hspace="5" vspace="5"', false, 4) . '</a><br />';
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It just changed the last parameter(thumbnail_type) in function tep_image() to the value I think it must be. I don't know why u set it to 5 there, let me know if I went wrong.
In additions, I think the constants [sMALL_IMAGE_WIDTH, SMALL_IMAGE_HEIGHT] should be changed to [PRODUCT_INFO_IMAGE_WIDTH, PRODUCT_INFO_IMAGE_HEIGHT] for independent setting (this constants was newly added by oscthumb installation, and it can be set in admin>Images).
Have fun!