some intermediate images shows smaller in size

[Mr.MEL]

In php when I called echo image with the dynamics path it shows some images in small size and some in actual size. most time the intermediate images are shown small in browser \[code\]<td align="center"><?php $image_path = "components/com_mediaonline/uploads/uploads/" . $row["photo_id"] . "/thumb/" . $row["filename"]; ?><a href="http://stackoverflow.com/questions/3634574/<?php echo $base_url ."&task=" . $operation_model_photoset_photo_click . "&photoset=" . $photoset . "&model_id=" . $model_id . "&filename=" . $row["id"] ;?>"><img style="border:2px solid #ccc;" src="http://stackoverflow.com/questions/3634574/<?php echo $image_path; ?>" alt=""></a></td> \[/code\]what you think whould be the reason for this