Locking up

when surfing the net the modem locks up every 5 or 6 mins for about 30 to 60 secs. Could it be the ISP (Paradise) or something else.
Anybody else got this problem which has only happened in the last week or so.

i had same problem turned out to be xtra's exchange, had to make a lot of noise to get them to fix it,appears to have been a data transfer problem??