PaulS:
if(client2.available() == 0) delay(5000);You seem completely fixated on doing nothing as much as possible. Someday, I hope you wake up and smell the coffee. When there is something to do, such as read data from the client2 instance, do it. When there is nothing to do, look for something else to do.
void loop(void) {
EthernetClient client2;
delay(1000);
Here's another example. On EVERY pass through loop(), you waste a full second. Why?
because otherwise it seems to take the reading too fast and alot of the times not get any data..
since this might be a good project for people with the blueiris camera software maybe if you feel like it you could rewrite it to be more professional and clean so other people can use it if they want. im sure im not the only person that wants arduino temp sensor overlays on their screens. on the pc side i have a loopign batch program run a python script in a hidden background to constantly update the text files containing the sensor information