Subpanels again

[Doorn]

Greetings,

When in the campaign list I click on a campaign, I get the detail view of that campaign, but without the subpanels below the campaign overview.
Instead of the panels I get these errors:

Warning: asubpanel(modules//subpanels/.php) [function.asubpanel]: failed to open stream: No such file or directory in /home/doornweb/public_html/scrm/include/SubPanel/SubPanelDefinitions.php on line 66

Fatal error: asubpanel() [function.require]: Failed opening required 'modules//subpanels/.php' (include_path='.:/usr/lib/php') in /home/doornweb/public_html/scrm/include/SubPanel/SubPanelDefinitions.php on line 66

This happens with all of my campaigns. These errors started to happen after appr. a week after I had started using SugarCRM.
I'm using Version 4.5.1b (Build 1246).

I read some postings on the forum concerning problems that are somewhat like mine, but none of them seem to exactly address my 'problem'.
Does anyone have any idea how I can fix this in my installation?
What can have caused it? Is it database related?

Kind regards,
Marcel

[jli]

Have you previously installed/uninstalled other modules (from the forums or SugarExchange)?

[Doorn]

Have you previously installed/uninstalled other modules (from the forums or SugarExchange)?

I installed a dutch language pack immediately after I installed SugarCRM. That's the only addon I have installed.
Furthermore, I don't recall having done anything special immediately before the error ocurred.