White spaces in graphs

[CacHNW]

Hello, I'm newbie in Cacti and I found it as very great tool. I'm monitoring a few of servers with PerfMon script from this forum. But one of servers is far away from me, so sometimes answer on value don't come and on graph for this host is white space. Is there any possibilities how to resolve this problem? For example enlarge timeout or add tries to get value. My idea is:
1) try to get value for the first time
2) if value is not valid, try it for the second and third time
3) if value is not valid too, put the last correct value to the graph

Is it possible?
Thank you