TimerDiff results in negative values and resets.

[Zoster]

I'm getting strange results from TimerDiff in the following setup:

Global $gt_TimerLastAction = TimerInit()

While True
	_SomeFunc1()
	_SomeFunc2()
	_TimerTest()
	Sleep(100)
WEnd

Func _TimerTest()
	$t_TimerDiff = TimerDiff($gt_TimerLastAction)
		Switch $t_TimerDiff
			Case 0 to 45000
				;Wait aleast 45sec
				ConsoleWrite("Still under 45sec: " & $t_TimerDiff & @CRLF)
				Return
			Case 45001 to 99000
				;Do action
				ConsoleWrite("Action: "& $t_TimerDiff & @CRLF)
				$gt_TimerLastAction = TimerInit()
				Return
			Case Else
				;Action overdue, reset
				ConsoleWrite("Overdue:" & $t_TimerDiff & @CRLF)
				$gt_TimerLastAction = TimerInit()
				Return
		EndSwitch
EndFunc

The first call produces a negative diff of -1864.62581138106.
In between the diff sometimes gets reduced from eg 14028.177324213 to 9461.37763319081 (between two case 45001) and some negative values also appear from time to time.

The variable is not being reset anywhere else in the program.

As far as I understand the TimerDiff function a negative value should be impossible.
Might this be a variant conversion problem or can the timer be reset anywhere else?

The application runs with AutoIt 3.3 on WinXP SP3 (Ger). It also uses some CommPort UDF (CommMG) and is remote controlled via Dameware.

[Zoster]

The problem is actually reproducable with the mockup code from above which I didn't expect. The code runs fine on another machine. My main suspect has become the CPU which is a AMD Geode.

From CPU-Z:

CPU-Z 1.50 report file
Processor(s)
Number of processors 1
Number of cores 1 per processor
Number of threads 1 per processor
Name AMD Geode LX
Code Name Castle
Specification Geode(TM) Integrated Processor by AMD PCS
Package Socket 481 BGU
Family/Model/Stepping 5.A.2
Extended Family/Model 5.A
Core Stepping
Technology 0.13 um
Core Speed 499.9 MHz
Multiplier x Bus speed 15.0 x 33.3 MHz
Rated Bus speed 66.7 MHz
Instruction sets MMX (+), 3DNow! (+)
L1 Data cache (per processor) 64 KBytes, 16-way set associative, 32-byte line size
L1 Instruction cache (per processor) 64 KBytes, 16-way set associative, 32-byte line size
L2 cache (per processor) 128 KBytes, 4-way set associative, 32-byte line size
Chipset & Memory
Southbridge AMD ID2090 rev. 03
Memory Type
Memory Size 224 MBytes
System
System Manufacturer
System Name
System S/N
Mainboard Vendor
Mainboard Model AMD-GX3
BIOS Vendor Phoenix Technologies, LTD
BIOS Version 6.00 PG
BIOS Date 03/13/1907
Memory SPD
Software
Windows Version Microsoft Windows XP Professional Service Pack 3 (Build 2600)
DirectX Version 9.0c

[Valik]

Closing as works for me.