#Requires doesn't see the module, Import-Module works

When I run a simple script with #Requires -Version 4 -Modules TestModule statement at the first line, I get an error:

The script 'TestScript.ps1' cannot be run because the following modules that are specified by the "#requires" statements of the script are missing: TestModule CategoryInfo : ResourceUnavailable: (TestScript.ps1:String) [], ScriptRequiresException FullyQualifiedErrorId : ScriptRequiresMissingModules

Some interesting facts:

1. The second time I run this script (same session), the module is loaded and everything works.
2. Script directory is on a network share, but 7 other modules load without any problems (module types are Manifest, Script and Binary - they all worlk).
3. One of the modules also has #Requires -Version 4 -Modules TestModule statement, but when I run a script with #Requires pointing to that module, both modules are loaded without any problems.
4. Path is obviously added to PSModulePath.
5. Prior to running the script, Get-Module -ListAvailable does list TestModule and all its' commands.
6. Import-Module works the first time.
7. There may be something missing on the machine: anyone who logs on that computer is experiencing the same problem.

$PSVersionTable:

Name                           Value
----                           -----
PSVersion                      4.0
WSManStackVersion              3.0
SerializationVersion           1.1.0.1
CLRVersion                     4.0.30319.18444
BuildVersion                   6.3.9600.16406

I have no idea what's going on.

Found the reason. I replaced #Requires with Import-Module TestModule -Verbose and found out that one of the assemblies could not be loaded, generating an error, but due to $ErrorActionPreference=Continue the rest of the module loaded. It appears that #Requires behaves differently than Import-Module.