Dlo,

How are you?
Which series of the studiotech stands are you using?
http://www.studiotech.com/jsp/productSelection.jsp?type=stands

Is everything tight? Are they on carpet? The spikes may not be long enough or may need to be adjusted.
You might also consider lead shot or sand, this will make it heavier.

Tom


M80's VP150 QS8's Earthquake SuperNova MKV-15
Integra DTR-7.4 Outlaw 755 Outlaw M200's Outlaw ICBM