It may or may not. They spider dynamic pages, but I don't know about semicolons. I had a site I switched over to use semicolons, but Google didn't grab any of the dynamic pages. I switched it back to ampersands, and the next day Google tried to grab some semicolon pages, whatever that means.
That looks pretty good to me, guillermo5000, but I'll try to ask around as well. Yeah, judging from the results for inurl:ikonboard inurl:act it's at least possible--I see lots of similar url patterns indexed.
If you want other search engines to crawl you, you might thing about what another poster suggested too--having static-looking urls might help for other engines. But I think you'll be fine for Google.