>>A simple look at the underside of the mouse discovered the cause: there was a hair, right over the red eye :).
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>Off topic, have you been to the Petrovaradin Fortress? Saw it in two different shows today...
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>Update: given history, I should have specified as a visitor or tourist (sorry about that)
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>It interested me for the size and duration of its existence without being destroyed over history and the buildings and structures in the local town. Also, it's known as a haunted site I understand...
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>(sorry for the updates as well)

I actually lived in Petrovaradin during my third year of college. Not in the fortress itself, but about two kilometers south, in the village, which means I passed through the fortress twice a day. The university is on the other bank. And went up there several times during my college years, which would count as "as a tourist".

The whole area is a wine country; most of the older houses in the village are on a hillside, each with a cellar dug into the hill and extending tens of meters into it.

The size of the fortress is a bit of a legend, because the visible part is an unknown fraction of the actual size. The local lore says that the plans exist only somewhere in the archives in Vienna, and that any arbitrary number of people got lost in the catacombs and never went out. There's a story of several secret exits, even of a tunnel which goes beneath Danube and can be entered via a door in the pillar of the unseen bridge, i.e. the one which got bombed in 1941 (or was never finished); another places the entrance somewhere on the left bank. The local criminals allegedly use it as an escape route of the last resort. As a tourist (once with a school trip, I think in VI grade), you get a brief tour of the corridors, no more than 50m in, and then there are heavy bars so you can't go deeper.

A nice touch is the tower clock, where the hours hand is longer than the minutes hand - hours being more important than minutes in those years.