Reordering your code I get something that I assume does something like what you want:

use LWP::Simple;
@divs = map m{<div class=ipm8rpt>([^<]*)</div>}i, map { get $_ }
        'http://uptimemgr/saved/1358381265931.htm',
        'http://uptimemgr/saved/1375561135115.htm',
        'http://uptimemgr/saved/1388446037003.htm'
        ;
[download]

Of course, the regexp is a pretty weak attempt of capturing whatever is in the div, but if this is HTML your people have produced themselves, it might work well enough.