[Treker]

It's 2 of my first photos and the 2nd to last photo that have this problem,

Just a possibility, check the door seal. I've had similar results and found that the film was light struck from a bad foam seal.

[average-guy]

If it's not a door seal, I'd send it to Eric Hendrickson at pentaxs.com . My spotmatic had a similar issue, it was curtain bounce (only at 1/1000 second), the curtain brakes were no longer able to slow down the shutter curtain at that speed and it was bouncing back into the frame. After it came back it was "good as new", if you're planning on keeping and using the camera for a while, then I'd recommend having it repaired and CLA'd (cleaned, lubed, adjusted). You'll probably only have to do it once, because if you take care of it, it will be years, possibly a decade or two before it needs it again. And Eric's rates are very reasonable, My Spostmatic was $80 for the curtain brakes and a CLA.

Edit: If I remember correctly, the repair bill also included replacing one of the metering cells. The Spotmatic has two and apparently one of them was dead, I usually used the Sunny 16 rule with it so I never new.