Strange freeze before landing at EHAM (tutorial flight)

After having a quite smooth flight with almost no incidents, except the strange Radio Altimeter setting that wanted me to turn down from 34000 ft (it would have taken hours), I experienced a quite new experience on finals. I just had switched off the A/P in order to land manually when the screen became milky giving me the message that my computer ran out of memory. This is quite odd as I do have a Win 7/64bit system equipped with 16 Gig of memory. My rig:ASUS P8Z68-V, i7-2600K CPU @ 3.40GHz, Noctua NH-12P SE2 and 16 GB Kingston RAM,GPU: AMD HD 5870, 1024 MB,BE Quiet Dark Power Pro 650W However, there is a second issue:I'm using a registered UIPC giving me normally the opportunity to reload a flight a couple of minutes before the crash happened. This try caused a sudden crash of FSX giving my the advice while restarting to shut down the system before trying to start FSX again. I would accept that the FMC would be not be in its right state but there should be no crash. The Log points to PMDG's NGX gauge and says:

- <Event xmlns="http://schemas.microsoft.com/win/2004/08/events/event">    - <System>            <Provider Name="Application Error" />            <EventID Qualifiers="0">1000</EventID>            <Level>2</Level>            <Task>100</Task>            <Keywords>0x80000000000000</Keywords>            <TimeCreated SystemTime="2011-08-06T22:22:13.000000000Z" />            <EventRecordID>4508</EventRecordID>            <Channel>Application</Channel>            <Computer>xxxxx</Computer>            <Security />        </System>- <EventData>            <Data>fsx.exe</Data>            <Data>10.0.61637.0</Data>            <Data>46fadb14</Data>            <Data>PMDG_737NGX.DLL</Data>            <Data>1.0.0.0</Data>            <Data>4e3afb98</Data>            <Data>c0000005</Data>            <Data>0019fe35</Data>            <Data>38c8</Data>            <Data>01cc5486fc78e07d</Data>            <Data>D:\Flightsims\Microsoft Flight Simulator X\fsx.exe</Data>            <Data>D:\Flightsims\Microsoft Flight Simulator X\GAUGES\PMDG_737NGX.DLL</Data>            <Data>883b5795-c07a-11e0-8ebb-f46d0459276f</Data>        </EventData>    </Event>

Remark: As this entry exists twice in the log it reflects likely just the second issue. What the heck is going on???? Regards,Axel