Can't see any files in the "Temporary Internet files" folder, it looks like empty. But I can see them when I open the Windows explorer.
Where is the 'Tweek'? (if any).
And another thing, I 'decorated' the files window (in Dopus) with some backround patern, all is well until I open the History folders, and there, part of the patern where the "Internet Host" column (list of URL's) is missing.
Thanks in advance.
Presumably you have set Opus not to show hidden and/or system files? If you view Temporary Internet Files as a real folder then the contents are hidden/system files so this would explain why you aren't seeing anything at all.
If you want to view Temporary Internet Files the same way that Explorer does (a virtual view on the IE cache rather than the actual files below that folder) then make sure you have Treat all "virtual filesystem folders" as virtual selected under Preferences / Folders / Virtual Folders (or, if you have the bottom option selected, make sure you haven't included the Temporary Internet Files in the list of virtual folders to treat as real).
History is another virtual folder, although it sounds like you're seeing it as a virtual folder unlike Temporary Internet Files which you're probably seeing as a real folder. Virtual folders (when viewed as virtual folders rather than their real on-disk contents) are always handled using Explorer and the background pattern stuff is limited because Opus doesn't have much control over how Explorer draws things. In this case your images is probably being blocked out for that column because it's the sort column and is thus drawn in a different colour to the rest of the background.
(If you don't get any background images at all in virtual folders it's probably because Preferences / Display / Options: Enable background images in virtual folder is turned off.)