I have the same problem and I too really wonder if there's any soultion to it.
Deep Fritz 12 - full analysis settings
Just tried what you suggested, still rushes through in less than half a minute (at depth 20), thanks for trying to help though, any other thoughts :)?
Going slightly off topic are you suggesting that move by move analysis (obviously skipping obvious moves) might be as effective if not even more effective than complete analysis?

I'm using Fritz 12 on a dual core PC and I usually set it for 3 hrs a game unless the game is esp long or complicated. It's usually only good for pointing out some of my blunders, it often will rate my game as =, ignore several moves and then announce I'm busted. It seems to be best at analyzing in infinite search mode when you can see several lines (or more) on every move, and start playing out the lines that interest you the most (and writing them down or saving them in Fritz)
You can try using these awesome free engines in Fritz as well: Stockfish, Firebird and Houdini IF they will work in Deep Fritz. You should also make sure Fritz is actually taking advantage of your quad core cpu AND give it as much RAM to use as you can spare, in multiples of 2 squared ie 2-4-8-16-32-etc. At least this is the advice given for Fritz 12.
I'd be interested to know if any of the suggestions you get here work!
I really appreciate all the tips I've been given here and will come back either tonight or tomorrow letting you know if I managed to get the hang of it! :)

how to set deep fritz 8 to play various openings, I have one old version, fritz8 but when I play d4 he always plays nimzo-indian. and he always play me e4.

Is the chess.com analysis engine as good as fritz?
NO I have Fritz 12 and I've had games analyzed here - chess.coms analysis is better than nothing but you have no control over whatever secret engine or program they use here that is you can't set a TL per move or game, can't set the ply depth of search per move etc. You can do that and lots more with Fritz, for instance set Fritz on infinite analysis of each move and examine a few or several different lines of play at every move, from best to worst lines for the side with the move.
Does anyone know what reasonable settings are for full analysis on Deep Fritz? I've got a relatively recent quad-core machine, and it always completes the analysis in less than a minute. I've tried upping both the per-move and per-game time settings, but it seems to be ignoring them. Suggestions?