Water cooling Air Problem

I've gotten brave and took my water cooling setup and put it on my main system.

Here's my setup :: DD cube radiator, DD maze block, Rio 180 pump in 2cool computer tank, 6' hose

It worked very well on my amd 500mhz system and I had no problems with it but now on my PIII system I am getting a weird "backflow" of air.

When I turn on the pump I get a good flow of water through the whole setup. When I shut it off I am getting air in the short tube that runs form the radiator to the intake on my reservoir. All the water runs back through the setup and air replaces it. I have hose clamps on all the connections so I don't think it's sucking in air. What's going on ? Is the air trapped in the system maybe ? How do I get it out if it is ? Any other ideas are needed. Please help me out, I've never had this problem.

Mine does the same thing,Its the trapped air in the reservoir To get rid of that problem you need to fill at the highest point with another opening at another high point to bleed the air out. However you should be fine as long as you don't have continuos bubbles in the system they should go away, mine does and I have no problems

Seems like the extra air doesn't have any effects on the system. I might just be paranoid, can't loose my baby it's all I got. Had her running during lunch break. Here's my temps.

room temp : 30C
case temp : 30C
Probe on main board under cpu (PIII 733)
bios : 26C
Gigabyte system monitor : 24C

Do these temps seem right or do I need to invest in a better temperature probe like the enermax ones that have popped up on the forms lately ?

Tell u what after the ordeal I went threw I dont trust any board probes.I would get another probe no matter what brand u will be amazed how inaccurate the board probes are.