Everything used to work fine in Ubuntu 10.04. Now, when I upgraded to 12.04 and installed seo power suite I have the same problem as described above.
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Rank Tracker v.6.1 Error Report
Date: 4/25/12 11:37 AM
OS name: Linux
OS Arch: i386
Java version: 1.7.0_03
JVM bitness: 32
Stack Trace:
org.mozilla.browser.MozillaException: java.lang.UnsatisfiedLinkError: Error looking up function 'gtk_init': /usr/lib/i386-linux-gnu/libgdk-x11-2.0.so.0: undefined symbol: gtk_init
at org.mozilla.browser.MozillaExecutor.mozInit(MozillaExecutor.java:209)
at org.mozilla.browser.MozillaInitialization.initialize(MozillaInitialization.java:141)
at com.agilemind.commons.application.controllers.ApplicationControllerImpl.start(ApplicationControllerImpl.java:105)
at com.agilemind.commons.mvc.util.ApplicationStarter.a(ApplicationStarter.java:32)
at com.agilemind.commons.mvc.util.ApplicationStarter.access$200(ApplicationStarter.java:42)
at com.agilemind.commons.mvc.util.c.run(c.java:1)
at com.agilemind.commons.gui.errorproof.b.execute(b.java:2)
at com.agilemind.commons.gui.errorproof.ErrorProofUtil.executeAsErrorProofThreadAndReturn(ErrorProofUtil.java:12)
at com.agilemind.commons.gui.errorproof.ErrorProofUtil.executeAsErrorProofThreadAndReturn(ErrorProofUtil.java:16)
at com.agilemind.commons.gui.errorproof.ErrorProofUtil.executeAsErrorProofThread(ErrorProofUtil.java:3)
at com.agilemind.commons.mvc.util.ApplicationStarter.startApplication(ApplicationStarter.java:28)
at com.agilemind.ranktracker.RankTrackerApplicationStarter.main(RankTrackerApplicationStarter.java:3)
Caused by: java.lang.UnsatisfiedLinkError: Error looking up function 'gtk_init': /usr/lib/i386-linux-gnu/libgdk-x11-2.0.so.0: undefined symbol: gtk_init
at com.sun.jna.Function.<init>(Function.java:179)
at com.sun.jna.NativeLibrary.getFunction(NativeLibrary.java:347)
at com.sun.jna.NativeLibrary.getFunction(NativeLibrary.java:327)
at com.sun.jna.Library$Handler.invoke(Library.java:203)
at $Proxy0.gtk_init(Unknown Source)
at org.mozilla.browser.MozillaExecutor$1.run(MozillaExecutor.java:169)

A guy from support wrote me that I used wrong java. That's their universal answer: "you have wrong java!!!".
Well, I tried all possible javas - oracle's java 6 and 7, openjdk. And every time a got the same error.
It seems that seo power suite is not supported in ubuntu since version 11.10 and they are not going to fix it. At least I could not find any clear instructions on how to make seo power suite work on 12.04 - neither in this forum nor from support.