Random Damage, Blocks re-appearing.

I am having players receive random damage, at no steady interval, and a few of my players are having blocks reappear while mining. (never for me)

Windows 7. x64
32bit java (using 64bit causes minecraft client to crash constantly)

Craftbukkit 289 (has been occuring since 271, with 4 updates between 289)

"%ProgramFiles%\Java\jre6\bin\java.exe" -Xms1024M -Xmx1024M -jar craftbukkit-0.0.1-SNAPSHOT.jar

Plugins Running
WormholeX-Treme .67
General 2.1
Bedrockgapinsurance
dynmap .12.1
growbie .5
iConomy 2.2b
MyHome 1.8
Permissions 2.0
Simpleshop 1.3


I am unable to replicate the problem when i am the only one on a test server i have set up. But once I start the live server, it continues. I use an exact copy of the current server, but it doesn't seem to have any issues until more players connect. My ram usage never goes above 75%, and CPU is steady at 25%. It is difficult to test with plugins as I can't get more that 1 or 2 users to participate in live testing. But none of the plugin threads I use mention anything about this issue.

 

I had a similar issue, with 3 players connected we would all experience random damage and random blocks would appear in chunks depending on Y height it could be a chunk of wood, leaves, gravel, ore blocks, and so on so forth. it seemed to stop when I disabled dynmap.

 

It does seem that dynmap was causing the issue, which is odd, as on the test server, it caused 0 problems.