I do not think it has got to do with registry changes u did, because I have also edited the registry and made it to 30...
what i suspect is, you are using ad version of flashget which shows banners on top and sometimes it causes the problem...
so its better to use shareware version...
the solution to this problem, as mentioned by flashget people is to delete cd_clint.dll under windows system directory let flashget work at shareware mode.
check this -
http://www.amazesoft.com/faq.htm#b34
I hope this helps you.
Deep