Alignment pins loose on 2-cavity mold

[jloader]

358-105-SWC (9mm Luger) mold
I've sent this to Lee support, but let's see if any of the members here have any tips or advise:

2 cavity mold, prepped/lubed smoked per directions have casted about 500 bullets.
Issue: mold halfs are loose/misaligned by 0.02".
When mold is closed I can "slide" the halfs - alignment pins are too far back in the mold. So I used a light tap on the back of the pins (with mold closed) to push them into the seats.
That works, tightens the alignment to 0.00 - perfect - for about 4-5 casts and then it's back to misalignment.
I have 3 molds in similar size and only this one seems to have an odd property: when knocking back the sprew plate, I have to use many more stokes and harder to move the sprew plate. Oddly enough, when without lead in the mold, the sprew plate moves back and forth very easily, gravity will slide it.
I tried different stages of cooling to hit sprew plate from semi-liquid to very solid sprew with same results.

I've gone thru Lee's Knowledgebase and found things about not overheating the mold - to my knowledge I stayed within the operating temps, did not keep the mold in the molten pot for more than 20-30 seconds.

Any thoughts/advise of the experienced members?

By the way, the "Bullet Casting" section does not have a specific area for "Molds" so I placed it here. Maybe that section could be added? Just a thought.
Thanks.

[daboone]

Take a look at castpics.net site http://www.castpics.net/subsite2/MoldMods/default.html

The site castpics is a treasure trove of useful information. The above link is just a small part of that site. ENJOY