Do timeframes influence EA start()?

I have a question about programming an EA. Does the start() function run at different times on different time frames?

The reason for this question is an EA I have that is set to a take profit of $100, and it trades 4 currency pairs. So when the combined trades reach 100, I close and start over. I send an email when this happens, and i just got an email saying it closed and reopened. I know that the actual profit might be off a couple of pips, but this trade closed with profit of 437.64. It is credited to my account and the prices are correct, but does the start() sometimes take a while to run. It was good for me today but there is always two sides to trading.

The start function is triggered on every new tick that comes in on the chart to which it is attached. If you have your EA on a GBPUSD chart, the EA will only call the start function for GBPUSD ticks.

For automated trading on multiple pairs, you really need to either code a multipart EA or write your logic as a script which iterates every half-second or so and runs through all your pricing logic. My preference is the second option.