Wi Fi Drop outs

hi there cats,
after having spent two days trying to get my ad hoc connection working,
bingo i have contact. But I now have the persistant problem of dropping out.
The host will search and find the client (with wi fi pc card), connect
beautifully, but drop the connection after @ 30 seconds and repeat the
search, find, drop out procedure automatically until i turn everything off in
frustration. The host is a Sony VAIO centrino equipped. The other is a
Gateway Solo.
Thanks for your suggestions.