Wix installer - cannot uninstall perUser package - wix

Question

After installation of perUser msi package I cannot uninstall it.
When selecting (Browse) package - that I installed - there is an error: 'selected package is not valid package for this product'.
Here's my code:
<?xml version='1.0'?><Wix xmlns='http://schemas.microsoft.com/wix/2006/wi'>
<Product Id='a871a539-5954-44b7-810d-caed5d09e4c5' Name='x' Language='1033'
Version='1.1.0.0' Manufacturer='M' UpgradeCode='a871a539-5954-44b7-810d-caed5d09e4c5'>
<Package Description='x'
Comments='x'
Manufacturer='x' InstallerVersion='200' Compressed='yes' InstallScope='perUser' />
<Media Id='1' Cabinet='product.cab' EmbedCab='yes' />
<Directory Id='TARGETDIR' Name='SourceDir'>
<Directory Id='AppDataFolder' Name='AppData'>
<Directory Id='xFolder' Name='x' />
</Directory>
</Directory>
<Component Id='xComponent' Guid='a871a539-5954-44b7-810d-caed5d09e4c5'
Directory='xFolder'>
<RemoveFolder Id="Removex" On="uninstall" />
<!-- registry entry to be used as keypath -->
<RegistryValue Root="HKCU"
Key="Software\M\x"
Name="component.xcomponent.installed"
Type="integer"
Value="1"
KeyPath="yes"/>
<File Id='myFile' Name='myFile.txt' DiskId='1' Source='myFile.txt' />
... files here
</Component>
<Feature Id='xFeature' Title='x feature' Level='1'>
<ComponentRef Id='xComponent' />
</Feature>
Installation process is ok - no errors. Files are in correct place. Registry key is added.
What am I doing wrong?

Answer 1

Yes - as Wim Coenen said - that question helped me resolve problem.
However instead of executing steps in that question I cleaned registry.
The problem was that I installed this package many times changing GUID and other parameters, so there was quite a mess in registry. I searched registry by Manufacturer and Name.
After cleaning up everything was ok.