FileAssembly and compression

<smartgwtVersion>3.1-p20140602</smartgwtVersion>
FF 24

Hi,

I'm trying to configure the FileAssembly and it is working so far. My problem starts when allowing the compression:
<compress>true</compress>

I get following error:



=== 2014-06-13 15:52:46,597 [80-4] INFO Compression - /wep/portal/portal.nocache.js: 6320 -> 2685 bytes
=== 2014-06-13 15:52:46,600 [80-2] INFO FileAssembler - read config file: C:/dev/wep/main/src/main/webapp/fileAssembly.xml
=== 2014-06-13 15:52:46,600 [80-2] INFO FileAssembler - Processing dynamically assembled file /wepAssembly.js
=== 2014-06-13 15:52:46,675 [80-2] ERROR FileAssembly - Top-level servlet error:
java.lang.AbstractMethodError: com.isomorphic.compression.Compression.compressBuffer([BLjava/lang/String;)Ljava/io/ByteArrayOutputStream;
at com.isomorphic.assembly.FileAssembler.assemble(FileAssembler.java:575)
at com.isomorphic.assembly.FileAssembler.assembleFile(FileAssembler.java:368)
at com.isomorphic.assembly.FileAssembler.assembleFile(FileAssembler.java:344)
at com.isomorphic.servlet.FileAssembly.doGet(FileAssembly.java:93)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:617)
at com.isomorphic.servlet.BaseServlet.service(BaseServlet.java:152)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
.
.
.
.
.

at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:489)
at java.lang.Thread.run(Unknown Source)
=== 2014-06-13 15:52:49,036 [80-6] INFO Compression - /portal/sc/DataSourceLoader: 1160113 -> 104882 bytes

I have already the Compression filter enabled for other URLs.

Regards
zapryano