This is certainly not normal behavior. My first guess would be a corrupt installation of Premiere.
As a test, try playing one of yoru sped up clips outside Premiere. The KM Player or VLC, or example.
Try capturing with Scenalyzer. Much better than PR. If you still have this problem, something else is amiss and you need to give more details on your settings and workflow.
i tried what jim sugested and played one of the clips in windows movie player (only because that what aiv opens with by default) and it played fine. So the problem is with premiere. i noticed when i put a sped up clip in to the timeline it has the red bar above it that shows it is unrendered. when i render it it stays the same and the speed is set to 100% nothing abnormal.
Next step is some details. What model DV camera? How is it connected? What are your capture settings? What are your sequence settings?
the camera is a panasonic pv-gs80 that im useing as a capture cam for my sony dcr-vx2000. i have used this meny time with cs3 and cs4 with no problem. the camera is connected through the built in 1394 port on my dell insperon 1525.
my sequence setting are
editing mode: DV NTSC
Timebase: 29.97 frames/second
Frame size: 720x480
pixel aspect ratio: D1/DV NTSC (0.9091)
fields: lower field first
Display format: 30FPS drop-frame timecode
sample rate: 48000Hz
display format: audio samples
preview file format: NTSC DV
Codec: NTSC DV
maximum bit depth is unchecked
My capture settings are:
Capture Format: DV
Capture locations are same as project
Device: DV/HDV Device control
DV/HDV Device control settings are:
video standard: NTSC
Device brand: Panasonic
Device type: standard
timecode format: auto detect
preroll time: 2s
timecode offset: 0f
hope all that could help
Now, I don't see anything you're doing wrong. Things should work fine.
Next would be to follow Harm's advice and try another capture utility. Scenalyzer or WinDV. Try those clips in Premiere and see how they work.