Pinging works, data doesn't

[Ym1]

Hi,
I hope u guys will be able to help me... i'm struggling with this issue quite a while.
I've got a win7 host, with a VirtualBox Host-Only Network adapter, automatically configured to 192.168.56.1/24 IP.
My Guest is RedHat 5.4, with an 192.168.56.101/24 IP. Mask is 255.255.255.0 at both.
DHCP is activated for the adapter, exactly as it should be according to the other posts here around.
I'm trying to connect with two tiny apps - host's app binds to 192.168.56.1, sends to 192.168.56.101, guests does the opposite.
For some reason ping works perfectly both ways, but not data transfer...
Do you have any word of advice?
Thanks a lot...

[noteirak]

If pings work both way, it means that there is no issue with the setup, simply something higher level actually not working (applications, software firewall, etc)

You talk about data transfert doesn't work - what kind of data transfert? how? what soft do you use?
You should check if the firewall of your host & guest is enabled or not. If it is, you should check that it will allow what you want