Problem installing programs on c500

[Guest gwiddecombe]

Hi, I'm sorry if this has been covered before but I'm having problems installing a number of programs on my C500 (which i decertified using OTA at Orange developers site). One example includes OmniGSoft Mini Sports bike (trial). Although it says its for smartphone 2003 I get the following message during install:

[filename].CAB failed to install on your device because the installation file is not intended for this device.

I would be really grateful if anyone could advise me please?

Thanks,

Graham