Avatar size limit

I changed my avatar size to 200 x 200 pixels max in avatar management, and went to my profile to test it out etc, all worked fine.

A few days later I come back to my admin panel and the size limit has been reduced to 150 x 180 pixels. I did not do this and I am the only admin. It's done this twice now.

So why is my forum mysteriously altering my settings for me???

beats me???
the only thing i can say is to just set it back again. i never heard of anything like that so i don't know what to suggest other re-setting it.