I am going to check on my stuff tonight, I've had a bunch of games in these pages for years...I'm sure it varies by material/age/exposure to light/humidity/etc.
Still, I'm gonna pull 'em out.
I should point out that there were different suppliers/manufacturers for the original HuCARD sleeves (or, alternatively, the manufacturers used different materials at different times)...consequently, some folks here have reported similar problems with SLEEVES adhering/damaging HuCARDS.
To prevent any damage, I now keep all of my HuCARDs in ceramic mugs and lace baggies*.
* baggies are free of polyvinyl and stuff like that....