File download access denied even for user 1

There seems to be an issue with downloading files as a someone with administrative role from user's (customer's) File downloads tab.

Here is what happens:

• common user comes to the website, buys a file; file is being added to user's File downloads tab in profile
• as user who bought the file, click the file and download should be offered
• now login as superuser 1 (admin) and go to the customer's user profile (the one that bought file few steps above)
• go to user's File downloads tab and click the file
• instead of download you will be thrown to "Access denied" page

Why?
Here is a reason:

• when you click on file function _uc_file_download in uc_file.pages.inc (line 187) triggers
• on line 203 in mentioned function there is this line which is problematic:
  $file_download = uc_file_get_by_uid($user->uid, $fid);
• function uc_file_get_by_uid is defined in uc_file.module on line 1557
• it checks through query user and file and builds cache array which looks something like $cache[$uid][$fid], for example $cache[1][453] = false;
• so it returns as a result in this array FALSE instead data needed for user to init download
• after this function we return to _uc_file_download and there we check what was returned. This is a critical line that makes an issue:
  line 205: if (isset($file_download->filename)) {

Because $file_download contains content of $cache array from uc_file_get_by_uid() it wont have filename as its only returned false so execution jumps to else which says:
return MENU_ACCESS_DENIED;
which results in showing everyone (superuser 1 included) access denied error. No permission can help here, and I believe this is a bug in code logic. The reason I believe so is that the same feature works perfectly fine on D6. There superuser or any role with correct permission can download other user's (customer's) file with no problem.

I googled a lot this issue and couldn't find any hints, patches or topics about this issue, so pardon if I missed some already existing topic.