.sis files won't install on nokia 6600

allo,

i downloaded .sis and .jar programs from handango for my nokia 6600. i
copied them onto my memory card from my PC, and put the files in the
root directory on the memory card. then i put the card in the nokia
6600 and tried installing the software. the .jar files worked fine, no
problems.

the .sis files will not install. the install option comes up and i
select it, but the .sis files won't install. i tried bluetooth and
sent the files to my phone. the .jar ones worked perfectly, but the
..sis files did nothing. after that i tried moving the .sis files into
my 'installed files' folder on the phone memory, then the programs
showed up in the 'application manager', but not in the phone menu. i
could look at the details and what version they were, but they still
weren't installed.

the programs i am trying to install are the alon mp3 player and the
phillips camcorder pro downloaded from handango, in case that makes any
difference.

also i do not use the nokia pc suite as i have not been able to make it
work with xp sp2, plus afterwards i heard it was near impossible to
uninstall.

any advice?

thanks in advance,
Walt