Hi Markus,
I just installed Opera and I see the problem as you reported.
The file names are actually buttons, ie input type=submit, but they are styled (at least in the other browsers) to look like links because we really don't want them to look like buttons. The reason we used buttons there is because ASP.NET LinkButtons don't work if javascript is disabled but normal buttons do. So for accessibility we went with buttons and then applied css to make them look like links. Apparently the css does not work as well with Opera.
The actual css is in the styletext.css file in each skin (located under /Data/Sites/[SiteID]/skins. If you edit the css you have to clear both the server cache and the browser cache to see your changes. Server cache is cleared by touching Web.config to recycle the app.
The relevant css is as follows:
.buttonlink {display:table-cell;background-color:transparent;border-style:none;color: #0033FF;cursor: pointer;text-decoration: underline; font-size: 9px;}
If you can help come up with css that still has the same effect in other browsers but can solve the problem for Opera, I would be glad to include the changes in the mojoportal skins. Of course on your own site you are free to make any changes you wish no matter the effect on other browsers.
Best,
Joe