cisco packet tracer issues

[aneksadh]

cisco packet tracer allows rip v1 routing with classless networks
it behaves funny

i configured f0/0 of router 1 with 10.0.0.0 network
i configured the 2 fast ethernet int's of router 2 with 192.168.10.0/25 & 192.168.10.128/25 networks

10.0.0.0 network pc can pin to both networks of router 2

that should not happen, right ?
sometimes it allows you to ping, sometimes it wont, and then when u change ripv 1 to 2 it allows u to ping and sometimes it wont, i went crazy

my trainer told me that this happens in cisco packet racer and suggested me to use GNS, i downloaded it and it's not that easy to use, i still am figuring our how to use gns

also cpt does not allow bundling of eigrp links, have u all faced this problem too,

rgds
anek