Could be an issue with your stepping size and not directly caused by the ppm (if that's what you meant by the 1000 reference). Try this to get things back in working order:
Set your ppm to 0, just for testing. Set the stepping size to 1 kHz for testing. Set the Sample Rate (under the RTL-SDR settings) to 1024 MPS again for testing.
Tune SDR# to 470.310 MHz which is one of the ATSC carrier signals here in the US (our digital TV system).
Look at where the actual peak of the signal appears on the spectrum, it'll either be to the left or the right of the centerline (and yes it could be very
very far off because the ppm is set to zero.
Decreasing the ppm will shift the peak to the left of center, increasing it shifts it right. Don't change the frequency info at this point, just start adjust the ppm one step at a time as needed, and continue adjusting it until the peak gets as close to the center as possible - don't waste time trying to get it
perfect - just get it as close as possible to the center. On one of my RTL sticks with the 55 ppm value, at 55 ppm it's just a hair to the right of center (this stick when warmed up would technically have something like a 54.655 ppm (that I've calculated) but it's not necessary to get it that precise.
Anyway, use the zoom feature of SDR# (slider on the upper right) to zoom in to about half-scale or 50% and look for the top of that peak and adjust till it's as close to center as you can with the ppm - it'll be either slightly left or right of it as noted and that's fine, that's what you're looking for.
Let the stick warm up for 5-10 mins just tuning that one frequency, you might even notice on the waterfall as the signal slowly shifts left or right during this process which is ok as well. After 5-10 mins when it's fairly consistent, and the ppm setting has the peak as close to center as it'll get
without adjusting the actual frequency you're tuned to or adjusting the stepping, you're done. You should only need to adjust the ppm basically one time - once the stick is warmed up and at operating temps, unless you stop using it (close SDR# or whatever) it should remain "on frequency" at the ppm you now have locked in for that stick - if you have multiple sticks, do the same process for each of 'em and perhaps even label them with a piece of tape or something with the ppm so you know at a glance what's what.
Set everything back to "normal" except for the ppm and you should be good to go. For my setup and that one stick, this is what mine looks like at 55 ppm on that frequency:
