Does anyone else experience this? In the tutorial, whenever the instructor says something, the voice-overs are cut off in mid-sentence near the end of his text, each and every time. It's ugly, to say the least, but seeing that you can still read what he meant to say it's not half as bad as the intro sequence from the actual game. In the cutscene, the speakers are cut off in mid-sentence, too, and as soon as one is cut off, the other one already speaks his next line which is also cut off before it's finished, and so on. Meaning the dialogue moves way too fast and I can't even read the subtitles unless I make a sport out of it. The game is next to unplayable for me this way, at least not enjoyable at all.

Any idea what could be the cause?

I believe that's all consequences of the game not playing well with multi-core processors. Set it to use a single core from the Task Manager. (Open the game, right-click the DeusEx.exe process, and select "Set Affinity...")

Thanks! I've tried that, but sadly to no avail. Not quite sure if it improves matters a little bit, maybe cutting off just every second sentence now, but it's still no fun. :(

I'm having the same issue with the sound being cut off at the end of every characters "speech." The game itself seems to run too fast. I'm running Windows 7 64-bit.

Update:
I have found that using the Kentie Launcher from here http://kentie.net/article/dxguide/ fixes the sound issue. Setting the game to full screen mode also makes it run better as well.

I'm willing to try that, but the mod sticky mentions the Kentie Launcher will cause the game to crash in one area? I have to admit I'm a bit overwhelmed with all the mod suggestions, not sure what to choose, if any, and how to install them ... On which Windows version did you try this? I've read that dgVoodoo 1.50 Beta2 is not fully compatible to Vista, is that true?

I have used it on both XP sp3 and win7 with no problems :)

It's only one area, and I made available a fixed version of the map where it occurs.

I didn't try the Kentie Launcher suggestion, since Stanski57's 3dfx glide solution seems to have worked for me already, but thanks a lot to all of you for your advice! :)

This fix also worked for me on XP sp3. Thanks everybody :)

Yes I got that playing with the OpenGL renderer.
What worked for me was I used MSI Afterburner to limit the game to 30 frames per second.

That also made the glitch go away.

This issue is not connected in any way with multi-core processors, since I have single-core one and it shows symptoms described in the original post. Also, the game runs ridiculously fast, rendering in unplayable.

Running it at Windows XP (SP3). For some reason Kentie's launcher (even old versions compatibile with XP) won't work for me (MSVCP110.DLL missing, despite having MS Visual C++ 2010 Redistributable Package (x86) installed).

MSI Afterburner won't work with my laptop's graphics card.
Switching to software rendering didn't help neither.

Could still be related to muli-core if you has a Pentium 4 HD.

Sounds like you may have Intel SpeedStep or similar feature enabled on your motherboard. It is a function that dynamically changes your CPU clock during use and I know for a fact that it has this effect on Deus Ex and other unreal engine games of that era. My guess is that the engine assumes the CPU will stay at whatever it is (downclocked) to before the game launches, but as the game is more CPU intensive than idling in windows, it clocks up and the game runs at lighning speed because of it.

SpeedStep can be disabled in the motherboard BIOS settings as you boot up your computer.

For me the solution was to install the direct x10 renderer then switch on vsync in the advanced options for the renderer.