Welcome to RC-RP bamieham.
Well, since I recently checked - RC-RP is on 176.31.106.58:7777 and it is on SA-MP 0.3d.
Solution: This happens to some players in SA-MP, including me. So I suggest that you go to your security management and turn off the firewall. If I have my firewall on whilst on SA-MP, all the servers have [0/0 players] and [Ping 9999]. If I turn it off, it shows you the right amount of ping the server is having (below 200) and has a fair amount of players on it, that means it is working fine and you have access to the server itself.
If this doesn't work, please report the issue to me on what's happening when you turn the firewall off.
Sincerely, Jambo.