This is an air flow problem. One of these is a problem:
- Your tank doesn't have enough flow - unlikely
- Something (such as your ASA) is restricting air flow - also unlikely
- Your inline regulator needs to be cleaned - very likely
The problem is the inline regulator needs a particular hex socket wrench to disassemble. If you're able to, disassemble the inline reg, clean off the old lube, relube the o-rings and reassemble properly and recrono. If you're up to it, you should be able to find out how to disassemble the reg from your manual or www.zdspb.com
If you're uncomfortable doing this, I suggest you take it to a local proshop or someone else qualified to do this; the last thing you want is to make things even worse.